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Combinación de formoterol y budesonida como tratamiento de mantenimiento y alivio versus la mejor práctica actual (que incluye el mantenimiento con esteroides inhalados) para el asma crónica en adultos y niños

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Resumen

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Antecedentes

Tradicionalmente el tratamiento inhalado para el asma ha empleado tratamientos separados de prevención y alivio. La combinación de formoterol y budesonida en un inhalador ha permitido un inhalador único para la prevención y el alivio de los síntomas (tratamiento con un solo inhalador).

Objetivos

Evaluar la eficacia y la seguridad de formoterol y budesonida en un solo inhalador para el tratamiento de mantenimiento y alivio del asma en comparación con mantenimiento con corticosteroides inhalados (CSI) (solos o como parte de la mejor práctica actual) y cualquier tratamiento de alivio.

Métodos de búsqueda

Se hicieron búsquedas en el registro de ensayos del Grupo Cochrane de Vías Respiratorias (Cochrane Airways Group) en febrero de 2013.

Criterios de selección

Ensayos controlados aleatorios paralelos de 12 semanas o más de duración en adultos y niños con asma crónica. Los estudios tenían que evaluar la combinación de formoterol y budesonida como tratamiento con un solo inhalador versus un grupo control que recibió esteroides inhalados y otro inhalador de alivio.

Obtención y análisis de los datos

Se utilizaron los procedimientos metodológicos estándar previstos por Cochrane.

Resultados principales

Se incluyeron 13 ensayos en los que participaron 13 152 adultos y en uno de los ensayos también participaron 224 niños (que se informaron por separado). Todos los estudios fueron patrocinados por el fabricante del inhalador para el tratamiento con un solo inhalador. Nueve estudios que evaluaron el tratamiento con un solo inhalador versus la mejor práctica se consideraron con bajo riesgo de sesgo de selección, pero con alto riesgo de sesgo de detección porque no fueron cegados.

En los adultos con asma que no estaba bien controlada con los CSI, la reducción del ingreso hospitalario con el tratamiento con un solo inhalador no alcanzó significación estadística (odds ratio de Peto [OR] 0,81; intervalo de confianza [IC] del 95%: 0,45 a 1,44; 8 ensayos, n = 8841, pruebas de calidad deficiente debido al riesgo de sesgo de detección en los estudios abiertos y a la falta de precisión). Las tasas de ingreso hospitalario fueron bajas; por cada 1000 pacientes tratados con la mejor práctica actual seis experimentarían un ingreso hospitalario en el transcurso de seis meses, en comparación con entre tres y ocho en los pacientes tratados con un solo inhalador. Las probabilidades de presentar exacerbaciones que necesitaron tratamiento con esteroides orales fueron menores con el tratamiento con un solo inhalador comparado con control (OR 0,83; IC del 95%: 0,70 a 0,98; 8 ensayos, n = 8841, pruebas de calidad moderada debido al riesgo de sesgo de detección). Por cada 100 adultos tratados con la mejor práctica actual durante seis meses, siete requirieron un ciclo de esteroides orales, mientras que con el tratamiento con un solo inhalador lo necesitarían seis (IC del 95%: 5 a 7). La reducción pequeña en el tiempo hasta la primera exacerbación grave que necesitó intervención médica no fue estadísticamente significativa (cociente de riesgos instantáneos [CRI] 0,94; IC del 95%: 0,85 a 1,04; 5 ensayos, n = 7355). La mayoría de los ensayos demostró una reducción en la dosis diaria total media de los CSI con el tratamiento con un solo inhalador (la reducción media se basó en los datos autoinformados de los diarios de los pacientes y varió de 107 a 385 µg/día). Los retiros debido a eventos adversos fueron más frecuentes en los pacientes con tratamiento con un solo inhalador en comparación con la mejor práctica actual (OR 2,85; IC del 95%: 1,89 a 4,30; pruebas de calidad moderada debido al riesgo de sesgo de detección).

Tres estudios con 4209 adultos compararon el tratamiento con un solo inhalador con el tratamiento de mantenimiento con budesonida a dosis más altas y terbutalina para el alivio de los síntomas. Los estudios presentaron un bajo riesgo de sesgo. La implementación de estos estudios incluyó el retiro de los agonistas beta de acción prolongada y los pacientes se reclutaron si estaban sintomáticos durante la implementación. La reducción de las probabilidades de hospitalización con el tratamiento con un solo inhalador en comparación con CSI a dosis mayor no alcanzó significación estadística (OR de Peto; 0.56; IC del 95% 0,28 a 1,09; pruebas de calidad moderada debido a la falta de precisión). Menos pacientes con tratamiento con un solo inhalador necesitaron un ciclo de corticosteroides orales (OR 0,54; IC del 95%: 0,45 a 0,64; pruebas de alta calidad). Por cada 100 adultos tratados con CSI durante 11 meses, 18 requirieron un ciclo de esteroides orales, mientras que con el tratamiento con un solo inhalador lo necesitarían 11 (IC del 95%: 9 a 12). Los retiros debido a eventos adversos fueron menos frecuentes en los pacientes con tratamiento con un solo inhalador en comparación con mayores dosis de budesonida de mantenimiento (OR 0,57; IC del 95%: 0,35 a 0,93; pruebas de calidad alta).

Un estudio incluyó niños (n = 224) en los que el tratamiento con un solo inhalador se comparó con budesonida a dosis mayores. Con el tratamiento con un solo inhalador hubo una disminución significativa de los participantes que necesitaron aumentar sus esteroides inhalados, pero hubo sólo dos hospitalizaciones por asma y ningún dato separado sobre los ciclos de corticosteroides orales. Se utilizaron menos corticosteroides inhalados y orales en el grupo de tratamiento con un solo inhalador y la ganancia de talla anual también fue 1 cm mayor en este grupo (IC del 95%: 0,3 a 1,7 cm).

Los resultados para los eventos adversos graves mortales fueron demasiado poco frecuentes para descartar cualquier efecto perjudicial de los tratamientos. No se encontraron diferencias significativas en los eventos adversos graves no mortales en las comparaciones.

Conclusiones de los autores

Ahora se ha demostrado que el tratamiento con un solo inhalador reduce las exacerbaciones que requieren corticosteroides orales frente a las estrategias de mejor práctica actual y frente a una dosis mayor fija de esteroides inhalados. La fortaleza de las pruebas de que el tratamiento con un solo inhalador reduce la hospitalización versus estos mismos tratamientos es débil. Hubo más interrupciones debido a eventos adversos con el tratamiento con un solo inhalador en comparación con la mejor práctica actual, pero las diferencias no fueron significativas con respecto a los eventos adversos graves. La confianza en estas conclusiones es limitada por el diseño abierto de los ensayos y por el cumplimiento incierto del tratamiento en los brazos de mejor práctica actual de los ensayos.

El tratamiento con un solo inhalador puede reducir el riesgo de exacerbaciones del asma que requieren el uso de corticosteroides orales en comparación con dosis fijas de CSI de mantenimiento y medicación de alivio separada. La reducción en las probabilidades de exacerbaciones con el tratamiento con un solo inhalador en comparación con CSI a dosis mayores se debe analizar en el contexto de la repercusión posible del retiro de agonistas beta de acción prolongada durante la implementación del estudio. Lo anterior puede haber hecho que fuera más probable que las poblaciones de estudio respondieran al tratamiento con un solo inhalador.

El tratamiento con un solo inhalador actualmente no se autoriza en niños menores de 18 años de edad en el Reino Unido y en estos momentos existen muy pocas pruebas de estudios de investigación sobre este enfoque en niños o adolescentes.

PICO

Population
Intervention
Comparison
Outcome

El uso y la enseñanza del modelo PICO están muy extendidos en el ámbito de la atención sanitaria basada en la evidencia para formular preguntas y estrategias de búsqueda y para caracterizar estudios o metanálisis clínicos. PICO son las siglas en inglés de cuatro posibles componentes de una pregunta de investigación: paciente, población o problema; intervención; comparación; desenlace (outcome).

Para saber más sobre el uso del modelo PICO, puede consultar el Manual Cochrane.

Resumen en términos sencillos

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¿En los pacientes con asma el tratamiento con un solo inhalador que contiene formoterol y budesonida es mejor que la mejor práctica actual?


Antecedentes de la revisión
"Tratamiento con un solo inhalador" significa que se utiliza un inhalador único que contiene dos fármacos. Uno de estos fármacos actúa rápidamente y se le llama "de alivio". El otro funciona mucho más lentamente y se le llama "de prevención". El fármaco de alivio es un broncodilatador beta‐agonista que ayuda a abrir las vías respiratorias y ayuda a los pacientes a respirar más fácilmente. El fármaco de prevención es un esteroide que controla la inflamación subyacente en los pulmones que es causada por el asma. Los pacientes con "tratamiento con un solo inhalador" tienen un inhalador que se utiliza todos los días para controlar la inflamación subyacente y también para el alivio de los síntomas. La idea detrás del "tratamiento con un solo inhalador" es que cuando los pacientes utilizan los inhaladores para reducir la disnea o las sibilancias también reciben un aumento de la dosis del esteroide de prevención.

Se deseaba descubrir si el uso del tratamiento con un solo inhalador fue mejor o peor que otras opciones como recibir dos inhaladores separados para el tratamiento y el alivio regular de los síntomas.

¿Qué se hizo?
Se revisaron los ensayos clínicos que analizaron el tratamiento con un solo inhalador versus los esteroides inhalados y la medicación de alivio administrados en dos inhaladores separados (a veces llamada mejor práctica actual).

¿Qué se encontró?
Hasta febrero de 2013 se encontraron 13 ensayos con 13 152 adultos y un ensayo que también incluyó 224 niños. Los ensayos fueron patrocinados por el fabricante del inhalador único.

Cuando se comparó con la mejor práctica actual o dosis mayores de esteroides inhalados, se encontró que el tratamiento con un solo inhalador probablemente reduce el número de exacerbaciones que necesitarán tratamiento con un esteroide oral en adultos, pero no estuvo claro si se reduciría el número de adultos ingresados al hospital. Cuando se comparó con dosis altas de esteroides inhalados, se encontró que menos pacientes experimentaron exacerbaciones que necesitaran tratamiento con un esteroide oral.

Los resultados de muerte (uno por 1000 pacientes que recibieron cualquier tratamiento) o los problemas potencialmente mortales (solo menos de 50 por 1000 pacientes que recibieron cualquier tratamiento), fueron demasiado imprecisos para permitir determinar si un tratamiento fue más perjudicial que el otro. En el grupo que recibió inhaladores solos más adultos abandonaron el ensayo temprano porque presentaron efectos adversos. Solamente hubo un ensayo pequeño en niños, por lo que no se pueden establecer conclusiones firmes en los niños.

Generalmente los estudios estuvieron bien diseñados, aunque en los estudios que compararon el tratamiento con un solo inhalador versus la mejor práctica actual los pacientes conocían el tratamiento que recibían, lo que podría haber afectado la fiabilidad de los resultados. Los estudios que compararon el tratamiento con un solo inhalador versus esteroides inhalados tuvieron un diseño diferente y fueron más fiables. En general, se considera que más pruebas de ensayos futuros podrían cambiar la fortaleza de las conclusiones sobre la pregunta de si el tratamiento con un solo inhalador es mejor que la mejor práctica actual. Se considera que hay pruebas de buena calidad de que el tratamiento con un solo inhalador es más eficaz que altas dosis de esteroides inhalados, aunque los estudios reclutaron pacientes que tenían probabilidades de responder.

Authors' conclusions

Implications for practice

Guidelines suggest the addition of regular LABA or increasing the dose of ICS for asthma that is not controlled on regular low dose ICS. SiT did not significantly reduce exacerbations leading to hospitalisation in comparison with current best practice. However, SiT can reduce the risk of asthma exacerbations needing oral corticosteroids in comparison with fixed dose maintenance ICS, and to a lesser degree in comparison with current best practice in adults who were not well controlled on regular corticosteroids. There were more discontinuations due to adverse events on SiT compared with current best practice, but no significant differences in fatal or non‐fatal serious adverse events.

Our confidence in these conclusions is limited by the open‐label design of the trials that compared SiT with current best practice, and by the reliability of the self‐reporting of adherence to treatment in the trials. The main limitation of the results from studies comparing SiT with higher dose inhaled steroids was the possible selection of participants with diminished asthma control following the withdrawal of LABA during run‐in.

SiT is not currently licensed for children under 18 years of age in the United Kingdom and there is currently very little research evidence for this approach in children or adolescents.

Implications for research

More research is required on the efficacy and safety of SiT in children and adolescents, and on adults whose asthma is well‐controlled on low or moderate doses of ICS without additional LABA.

Summary of findings

Open in table viewer
Summary of findings for the main comparison. 160/4.5 mcg BDF single inhaler therapy compared to current best practice for adult asthma that is not controlled on ICS

160/4.5 µgBDF single inhaler therapy compared to current best practice for adults with asthma that is not controlled on ICS

Patient or population: adults with asthma that is not controlled on ICS
Settings: community
Intervention: 160/4.5 µg BDF single inhaler therapy
Comparison: current best practice

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Current best practice

160/4.5 µgBDF single inhaler therapy

Patients with exacerbations causing hospitalisation
Follow‐up: mean 6 months

6 per 1000

5 per 1000
(3 to 8)

OR 0.81
(0.45 to 1.44)

8841
(8 studies)

⊕⊕⊝⊝
low1,2

Patients with exacerbations treated with oral steroids
Follow‐up: mean 6 months

70 per 1000

59 per 1000
(50 to 69)

OR 0.83
(0.70 to 0.98)

8841
(8 studies)

⊕⊕⊕⊝
moderate1

Fatal serious adverse events
Follow‐up: mean 6 months

1 per 1000

1 per 1000
(0 to 5)

OR 1.95
(0.53 to 7.21)

8841
(8 studies)

⊕⊕⊝⊝
low1,2

Serious adverse events (non‐fatal)
Follow‐up: mean 6 months

20 per 1000

24 per 1000
(18 to 32)

OR 1.20
(0.90 to 1.60)

8841
(8 studies)

⊕⊕⊝⊝
low1,2

Discontinuation due to adverse events
Follow‐up: mean 6 months

7 per 1000

21 per 1000
(14 to 31)

OR 2.85
(1.89 to 4.3)

8411
(7 studies)

⊕⊕⊕⊝
moderate1

*The basis for the assumed risk is the mean control group risk across studies. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; OR: Odds ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Unblinded trials
2 Confidence interval cannot rule out important differences in either direction

BDF: budesonide plus formoterol; ICS: inhaled corticosteroids

Open in table viewer
Summary of findings 2. Single inhaler therapy compared to fixed dose ICS for asthma in adults not controlled on regular ICS

Single inhaler therapy compared to fixed dose ICS for asthma in adults not controlled on regular ICS

Patient or population: patients with asthma in adults not controlled on regular ICS
Settings: community
Intervention: Single inhaler therapy
Comparison: fixed dose ICS

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Fixed dose ICS

Single inhaler therapy

Patients with exacerbations causing hospitalisation
Follow‐up: mean 11 months

10 per 1000

6 per 1000
(3 to 11)

OR 0.56
(0.28 to 1.09)

4209
(3 studies)

⊕⊕⊕⊝
moderate1

Patients with exacerbations treated with oral steroids
Follow‐up: mean 11 months

181 per 1000

107 per 1000
(90 to 124)

OR 0.54
(0.45 to 0.64)

4280
(4 studies)

⊕⊕⊕⊕
high

Fatal serious adverse events
Follow‐up: mean 11 months

1 per 1000

1 per 1000
(0 to 4)

OR 0.37
(0.05 to 2.62)

4209
(3 studies)

⊕⊕⊕⊝
moderate1

Serious adverse events (non‐fatal)
Follow‐up: mean 11 months

48 per 1000

47 per 1000
(36 to 62)

OR 0.97
(0.73 to 1.29)

4209
(3 studies)

⊕⊕⊕⊝
moderate1

Discontinuation due to adverse events
Follow‐up: mean 11 months

36 per 1000

21 per 1000
(13 to 33)

OR 0.57
(0.35 to 0.93)

2586
(2 studies)

⊕⊕⊕⊕
high

*The basis for the assumed risk is the mean control group risk across studies. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; OR: Odds ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Confidence interval cannot rule out important differences in either direction
ICS: inhaled corticosteroids

Background

Description of the condition

There is currently no universally accepted definition of the term 'asthma'. This is in part due to an overlap of symptoms with other diseases such as chronic bronchitis, but is also due to the probable existence of more than one underlying pathophysiological process. There are, for example, wide variations in the age of onset, symptoms, triggers, association with allergic disease and the type of inflammatory cell infiltrate seen in patients diagnosed with asthma. Patients will typically all have intermittent symptoms of cough, wheeze, breathlessness or both. Underlying these symptoms there is a process of variable, at least partially reversible airway obstruction, airway hyper responsiveness and (with the possible exception of solely exercise‐induced asthma) chronic inflammation.

Description of the intervention

People with persistent asthma can use preventer therapy (usually low dose inhaled corticosteroid (ICS)) to maintain symptom control, improve lung function and reduce emergency care requirement. However, when symptoms deteriorate reliever medication in the form of short‐acting beta2‐agonists such as salbutamol or terbutaline, or formoterol (a fast‐acting but longer lasting formulation) can be used on an 'as‐needed' basis (SIGN/BTS 2012). Since most exacerbations have an onset over several days (Tattersfield 1999), there is potential for the person with asthma to increase both budesonide and formoterol at an early stage in response to increased symptoms of asthma. The pharmacological properties of another long‐acting beta2‐agonist (LABA), salmeterol, result in slower onset of bronchodilation (Palmqvist 2001), and it is not licensed for use on an 'as‐needed' basis. The inclusion of ICS in a reliever inhaler for use during episodes of loss of control requires monitoring and assessment of overall ICS dose (SIGN/BTS 2012).

How the intervention might work

The combination of ICS and LABA in one inhaler is an effective way of delivering maintenance anti‐inflammatory and bronchodilator therapy in chronic asthma (Ducharme 2010; Ducharme 2011; Ni Chroinin 2005; Ni Chroinin 2009). The anti‐inflammatory properties of the ICS and the bronchodilatory effect of the LABA play complementary roles in reducing inflammation in the airways and improving lung function with relief of symptoms related to bronchospasm (Adams 2008; Walters 2007). Both are recommended when low dose ICS alone is not sufficient to control asthma, which is at step three in British asthma guidelines (SIGN/BTS 2012). Concerns have been raised about the use of single inhaler LABA in chronic asthma, in particular where it is used without a regular ICS, in relation to the possible increased risk of severe adverse events and asthma‐related death (Cates 2008; Cates 2010a; Cates 2012a; Cates 2012b; Walters 2007). The concomitant delivery of ICS and LABA avoids the inadvertent use of LABA without prescribed ICS treatment (Cates 2009a; Cates 2009b).

Why it is important to do this review

It is recognised that many patients who are prescribed ICS do not take their inhaler every day, and combination inhalers can increase ICS use both as maintenance (Delea 2008) and single inhaler therapy (SiT) (Sovani 2008). Whilst the trials that have investigated doubling the dose of ICS early in exacerbations have been disappointing (FitzGerald 2004; Harrison 2004), there is the potential with SiT for the patient to automatically increase both LABA and ICS when their asthma is worse and cut down again as their symptoms improve. This holds out the prospect of maintaining control of asthma and preventing exacerbations with lower overall exposure to ICS.

This review has identified and summarised clinical trials that compare SiT for maintenance and relief with budesonide/formoterol against maintenance with ICS and a separate reliever therapy. The 2013 update to this review now includes data from an additional 4556 adults from trials comparing SiT with current best practice. The comparison of budesonide/formoterol for maintenance and relief against a higher dose maintenance ICS/LABA combination inhaler and a separate reliever therapy will be covered in another review (Cates 2011).

Objectives

To assess the efficacy and safety of budesonide and formoterol in a single inhaler for maintenance and reliever therapy in asthma compared with maintenance with inhaled corticosteroids (alone or as part of current best practice) and any reliever therapy.

Methods

Criteria for considering studies for this review

Types of studies

Randomised trials of parallel group design.

Types of participants

Adults and children with a diagnosis of chronic asthma. We accepted trialist‐defined asthma, recording the definition of asthma used in the studies, and the entry criteria. We did not include studies conducted in an emergency department setting.

Types of interventions

Eligible treatment group intervention

Combined inhaled steroid and long‐acting beta2‐agonist (LABA) delivered through a single inhaler device for regular maintenance and the relief of asthma symptoms.

Eligible control group treatment

Inhaled corticosteroid given as regular maintenance treatment with a separate reliever inhaler. This included "current best practice" according to local or international guidelines (which included an inhaled corticosteroid, GINA 2006).

We included studies lasting at least 12 weeks.

We did not consider studies that compared different combination therapy inhalers (regular fluticasone/salmeterol versus regular budesonide/formoterol has been reviewed elsewhere Lasserson 2008), or titration of maintenance dosing of combination therapy based on clinical signs and symptoms. Trials randomising participants to SiT versus a fixed dose combination inhaler are included in another review (Cates 2011).

Types of outcome measures

Primary outcomes

  • Patients with exacerbations requiring hospitalisation

  • Patients with exacerbations requiring oral corticosteroids

  • Serious adverse events (including mortality and life‐threatening events)

  • Growth (in children)

Secondary outcomes

  • Severe exacerbations (composite outcome of hospitalisation/emergency room (ER) visit/oral steroid course)

  • Diary card morning and evening peak expiratory flow (PEF)

  • Clinic spirometry (FEV1)

  • Number of rescue medication puffs required per day

  • Symptoms/symptom‐free days

  • Nocturnal awakenings

  • Quality of life

Search methods for identification of studies

Electronic searches

Trials were identified using the Cochrane Airways Group Specialised Register of trials, which is derived from systematic searches of bibliographic databases including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, CINAHL, AMED, and PsycINFO, and handsearching of respiratory journals and meeting abstracts (see Appendix 1 for further details). All records in the Specialised Register coded as 'asthma' were searched using the following terms:

("single inhaler therapy" or SiT or SMART or relie* or "as need*" or as‐need* or prn or flexible or titrat*) and ((combin* or symbicort or viani) or ((steroid* or corticosteroid* or ICS or budesonide or BUD or Pulmicort or beclomethasone or BDP or becotide) and ("beta*agonist" or "beta*adrenergic agonist" or formoterol or eformoterol or oxis or foradil)))

Date of last search was February 2013.

Searching other resources

We contacted trialists and manufacturers to confirm data and establish whether other unpublished or ongoing studies were available for assessment. We handsearched clinical trials web sites (www.clinicaltrials.gov and www.fda.gov) and the clinical trial web sites of combination inhaler manufacturers (www.ctr.gsk.co.uk; www.astrazenecaclinicaltrials.com).

Data collection and analysis

Selection of studies

Following electronic literature searches, two review authors (CC & TL or CK) independently selected articles on the basis of title and/or abstract for full text scrutiny. The authors agreed a list of articles which were retrieved, and subsequently assessed each study to determine whether it was a secondary publication of a primary study publication, and to determine whether the study met the entry criteria of the review.

Data extraction and management

We extracted information from each study for the following characteristics.

  • Design (description of randomisation, blinding, number of study centres and location, number of study withdrawals)

  • Participants (N, mean age, age range of the study, gender ratio, baseline lung function, % on maintenance ICS or ICS/LABA combination & average daily dose of steroid (BDP (beclomethasone dipropionate) equivalent), entry criteria)

  • Intervention (type and dose of component ICS and LABA, control limb dosing schedule, intervention limb dose adjustment schedule, inhaler device, study duration and run‐in)

  • Outcomes (type of outcome analysis, outcomes analysed)

We summarised baseline severity of lung function and persistence of symptoms, and collected data on pre‐study maintenance therapies.

Assessment of risk of bias in included studies

We assessed trial bias protection in the following domains study quality according to whether studies meet the following pre‐specified quality criteria (as met, unmet or unclear, Higgins 2008).

  • Random sequence generation (selection bias)

  • Allocation concealment (selection bias)

  • Blinding (performance bias and detection bias)

  • Incomplete outcome data (attrition bias)

  • Incomplete reporting of results (selective reporting bias)

Measures of treatment effect

We extracted data for each of the outcomes considered by the review from the trial publication(s) or from correspondence with the trialist or manufacturer. Exacerbations were the primary outcome for this review and were reported by subtype (hospitalisation and courses of oral steroids), rather than just as a composite outcome. Serious adverse events were considered separately as fatal and non‐fatal events.

Unit of analysis issues

We sought to obtain data from the trial sponsors that was reported with patients (rather than events) as the unit of analysis for the primary outcomes. Some patients may have suffered more than one exacerbation over the course of the studies and these events would not have been independent.

Data synthesis

Data were combined with RevMan 5.0, using a fixed‐effect mean difference (calculated as a weighted mean difference) for continuous data variables, and a fixed‐effect Odds Ratio for dichotomous variables. When zero cells were present for an outcome in any of the included studies the Peto Odds Ratio was used to combine the results as it does not require a continuity correction to be used. For the primary outcomes of exacerbations and serious adverse events, when a significant Odds Ratio was found, we calculated an number needed to treat (NNT) (benefit or harm) for the different levels of risk as represented by control group event rates over a specified time period using the pooled Odds Ratio and its confidence interval (Visual Rx).

Subgroup analysis and investigation of heterogeneity

We pooled data from adults and children in separate subgroups. Adult studies were considered as those that recruited participants from 18 years of age upwards. Adult and adolescent studies were considered as those that recruit participants from 12 years of age upwards. We considered participants in studies where the upper age limit was 12 years as children, and in studies where the upper age limit was 18 years as children and adolescents. Subgroup analyses were not possible in relation to asthma severity and degree of control of symptoms at baseline.

We measured statistical variation between combined studies by the I2 statistic (Higgins 2003). Where this exceeded 20%, we investigated the heterogeneity found, before deciding whether to combine the study results for the outcome.

Sensitivity analysis

Sensitivity analyses were planned on the basis of risk of bias in studies and methods of data analysis (fixed‐effect and random‐effects models).

'Summary of findings' tables

We applied methods recommended by the GRADE working group to rate the quality of evidence of SiT in adults. We present separate Summary of Findings tables for these two comparisons which also include estimates of the absolute effects based on the results of our analyses. We rated the quality of evidence for five main outcomes:

  1. Patients with exacerbations causing hospitalisation

  2. Patients with exacerbations treated with oral steroids

  3. Fatal serious adverse events

  4. Serious adverse events (non‐fatal)

  5. Discontinuation due to adverse events

Results

Description of studies

Results of the search

An updated search was carried out in February 2013 and identified 72 new abstracts (since the search in September 2008). These were independently assessed for inclusion by CJC and CK. Additionally, a new citation and two web‐reports were identified by handsearching the identifiers for the included studies (Riemersma (NCT00235911) and DE‐SOLO). One of the previously identified ongoing studies was excluded as it compared two different SiT regimens (EUROSMART or NCT00463866a). New reports were found on the AstraZenca web site for the five other studies comparing single inhaler therapy (SiT) with current best practice (PASSION; Riemersma (NCT00235911); SPAIN; STYLE; SYMPHONIE) and paper publications were also identified for SPAIN (Quirce 2011) and Riemersma (NCT00235911) (Riemersma 2012).

The search that was previously carried out in September 2008 included 198 citations. From these, 51 were retrieved as full text articles, representing 24 unique studies. There were originally 10 studies (21 citations) included in the review and 14 studies (31 citations) that were excluded. Full details are given in the lists of Included studies and Excluded studies.

Included studies

Five adult studies contributed new outcome data on 4560 adults and adolescents comparing SiT with current best practice for the 2013 update (DE‐SOLO; PASSION; SPAIN; STYLE; SYMPHONIE). Furthermore, new data on the characteristics of Riemersma (NCT00235911) are now available, indicating that this study recruited participants with well‐controlled asthma (FEV1 was nearly 100% predicted), and used a lower dose of budesonide/formoterol than the other studies comparing SiT with current best practice. This trial has therefore been considered in a separate comparison for the 2013 update. All of the included studies were sponsored or supported by AstraZeneca, the manufacturers of Symbicort.

Thirteen studies involved 13,152 adults and adolescents, and one study also recruited children (STAY ‐ Children). The results from the 224 children included in the STAY study were reported in a separate paper by Bisgaard 2006. This has therefore been regarded separately from STAY ‐ Adults, which reported the adult results from the STAY study.

Intervention

The active treatment in most studies was budesonide/formoterol 160/4.5 µg one inhalation twice daily plus as‐needed; this is the delivered dose and is the same as 200/6 µg actuator dose described in some of the studies. In STEAM and Riemersma (NCT00235911), the maintenance treatment inhaler was 80/4.5 µg given as two inhalations in the evening, and in STAY ‐ Children. The maintenance dose was budesonide/formoterol 80/4.5 µg one inhalation in the evening.

Of the 13 adult studies, nine studies compared SiT with current best practice; these were DE‐SOLO; MONO; Riemersma (NCT00235911); PASSION; SALTO; SOLO; SPAIN; STYLE and SYMPHONIE. In these studies long‐acting beta2‐agonists (LABA) were allowed in the control arm, and many of the participants were already using LABA when recruited. The only restriction on the current best practice group was that they must continue on inhaled corticosteroids (ICS).

The other four studies compared SiT with ICS as maintenance and terbutaline as reliever (Scicchitano 2004; STAY ‐ Adults; STEAM; Sovani 2008) and of these, the first three compared SiT with a higher dose of maintenance ICS. In these studies LABA were not allowed in the control arm, and were withdrawn from those patients previously taking them. Sovani 2008 compared to the same dose of ICS (as the main aim of this study was to assess compliance with ICS).

The reported mean daily dose of ICS previously used by participants was reported as: MONO (1035 µg), Riemersma (NCT00235911) (538 µg); SALTO (579 µg), Scicchitano 2004 (746 µg), SOLO (569 µg), Sovani 2008 (590 µg, but poor compliance was an inclusion criterion), SPAIN (1034 µg, BDP equivalent), STAY ‐ Adults (660 µg), STAY ‐ Children (315 µg), STYLE (506 µg) and SYMPHONIE (792 µg). The mean daily dose was lower in STEAM (340 µg) and was not available from PASSION or DE‐SOLO.

Inclusion criteria for DE‐SOLO, MONO, SALTO, SOLO, STYLE and SYMPHONIE were that the participants had to be stable on a combination of LABA and ICS or symptomatic on ICS maintenance, and 82% of the participants used LABA at study entry with an average ICS dose of 979 µg/day (BDP equivalent). PASSION, and SPAIN required adults to be symptomatic on ICS maintenance (with or without LABA). Scicchitano 2004, STAY ‐ Adults, and STAY ‐ Children included participants who had suffered a clinically important exacerbation in the previous year. In SALTO, 27% of patients were reported to have mild persistent asthma, 37% moderate persistent and 36% severe persistent.

Some studies included a run‐in of about two weeks in which LABA was withdrawn (Scicchitano 2004; STAY ‐ Adults; STAY ‐ Children; STEAM) and in the case of STEAM, the maintenance dose of ICS was reduced from an average of 350 µg/day to 200 µg/day as well, and in order to secure "a symptomatic population that could respond differently to different treatments, patients were required to have at least 7 inhalations of as‐needed medication during the last 10 days of the run‐in period". SALTO and SOLO continued usual therapy over the two‐week run‐in period, but details of any run‐in period are not currently available for the other studies.

Outcomes

The primary outcomes for the studies are shown in the Characteristics of included studies. For the majority of studies this was time to first severe asthma exacerbation, which usually included hospitalisation, visits to an emergency department (ED), a course of oral steroids for the studies comparing with current best practice. Sometimes a 30% drop in peak expiratory flow (PEF) was also counted as an exacerbation, such as in Scicchitano 2004; STEAM; STAY ‐ Adults; STAY ‐ Children. Sovani 2008 had a different design from the other studies and the primary outcome was the dose of ICS.

All of the studies (apart from Sovani 2008) are multicentre studies, and no information has been found in relation to differences between centres or countries in any of these trials.

Excluded studies

The reasons for the exclusion of 15 studies are documented in the Characteristics of excluded studies.

Risk of bias in included studies

An overview of risk of bias judgements is shown in Figure 1


Methodological quality summary: review authors' judgements about each methodological quality item for each included study.

Methodological quality summary: review authors' judgements about each methodological quality item for each included study.

Allocation

Demoly 2009 has reported details for six of the included studies indicating low risk of allocation bias. As the rest of the trials were also sponsored by the same manufacturer, the risk of selection bias was assessed as low.

Blinding

All the studies comparing SiT with current best practice were unblinded, and therefore were judged to be at high risk of performance and detection bias, whilst those comparing with higher doses of ICS were double‐blind and at low risk. Sovani 2008 was also unblinded as adherence was the primary outcome for this study.

Incomplete outcome data

There were imbalanced discontinuations in Riemersma (NCT00235911), SALTO, Sovani 2008 and SPAIN, and around 20% discontinuations in each group in PASSION. Othewise, the included studies were judged to be at low risk of attrition bias.

Selective reporting

Missing data from five large trials on 4556 adults (DE‐SOLO; PASSION; SPAIN; STYLE; SYMPHONIE) comparing SiT with current best practice have been included in the 2013 update of this review. We are therefore now less concerned about missing trial reports in relation to the primary outcomes of this review. However, we have still not been able to obtain data from STAY ‐ Children for the exacerbations requiring a course of oral corticosteroids.

Effects of interventions

See: Summary of findings for the main comparison 160/4.5 mcg BDF single inhaler therapy compared to current best practice for adult asthma that is not controlled on ICS; Summary of findings 2 Single inhaler therapy compared to fixed dose ICS for asthma in adults not controlled on regular ICS

The primary outcomes for this review were exacerbations leading to hospitalisation, exacerbations treated with a course of oral corticosteroids and serious adverse events. Initially the trials reported composite outcomes that include the above types of exacerbation combined with emergency room (ER) visits and sometimes a 30% drop in peak flow. We have obtained data on our primary outcomes from the trial sponsor and recent web reports (for the 2013 update). Most of the studies are also multi‐site randomised controlled trials and have not reported data from any of the individual sites.

Adults and adolescents treated with 160/4.5 µg single inhaler therapy (SiT) (twice daily and as‐needed) versus current best practice

Eight trials on 8841 adults and adolescents now contribute to this comparison for the 2013 update (DE‐SOLO; MONO; PASSION; SALTO; SOLO; SPAIN; STYLE; SYMPHONIE). All of these studies ran for six months and recruited participants whose asthma was not controlled in spite of regular inhaled corticosteroids, or who were on treatment with LABA and ICS at recruitment (around 80% of those recruited). We have presented the quality of evidence for relevant outcomes in summary of findings Table for the main comparison.

Primary outcomes
Exacerbations of asthma causing hospital admissions

There were 47 people who suffered one or more hospitalisations from a total of 8841 participants in the eight trials providing data for this outcome (21 in the SiT arms and 26 in the current best practice arms). SALTO reported two asthma exacerbations that required hospitalisation in the SiT arm of the study, and we have obtained confirmation from the sponsors that the two events were in separate participants. There was no significant difference in the pooled outcome: (Peto odds ratio (OR) 0.81; 95% confidence interval (CI) 0.45 to 1.44; low quality evidence due to risk of bias and imprecision), see Figure 2.


Forest plot of comparison: 1 Adults and Adolescents treated with Single Inhaler Therapy versus Conventional Best Practice, outcome: 1.1 Patients with exacerbations causing hospitalisation.

Forest plot of comparison: 1 Adults and Adolescents treated with Single Inhaler Therapy versus Conventional Best Practice, outcome: 1.1 Patients with exacerbations causing hospitalisation.

Exacerbations of asthma treated with oral corticosteroids

We originally obtained data from four studies (MONO, Riemersma (NCT00235911), SOLO and STYLE, 4470 participants) on patients with one or more courses of oral corticosteroids and the reduction with SiT was not significant at that time (OR 0.83; 95% CI 0.66 to 1.03; moderate quality evidence due to risk of bias).

However, with the update in 2013 there are now eight trials on 8841 participants contributing to the meta‐analysis and with the new data the reduction with SiT is now statistically significant (OR 0.83; 95% CI 0.70 to 0.98) see Figure 3. Three hundred and four out of 4408 participants (7%) were treated with oral corticosteroids using current best practice over six months, and this translates into a number needed to treat to benefit (NNTB) of 90 (95% CI 51 to 767), to prevent one patient needing oral corticosteroids over an 11‐month period, see Figure 4


Forest plot of comparison: 1 adults and adolescents treated with Single Inhaler Therapy versus Conventional Best Practice, outcome: 1.2 Patients with exacerbations treated with oral steroids.

Forest plot of comparison: 1 adults and adolescents treated with Single Inhaler Therapy versus Conventional Best Practice, outcome: 1.2 Patients with exacerbations treated with oral steroids.


In the current best practice group 7 people out of 100 had exacerbations treated with oral steroids over 6 months, compared to 6 (95% CI 5 to 7) out of 100 for the single inhaler therapy group. NNT(B) = 90, (95% CI: 51 to 767).

In the current best practice group 7 people out of 100 had exacerbations treated with oral steroids over 6 months, compared to 6 (95% CI 5 to 7) out of 100 for the single inhaler therapy group. NNT(B) = 90, (95% CI: 51 to 767).

Serious adverse events

No significant difference was seen in people who suffered a fatal or non‐fatal serious adverse event from the combined results of the eight trials on 8841 participants; for fatal events (Peto OR 1.95; 95% CI 0.53 to 7.21; low quality evidence due to risk of bias and imprecision) Analysis 1.3, and for non‐fatal events (OR 1.20; 95% CI 0.90 to 1.60; low quality evidence due to risk of bias and imprecision) Analysis 1.4. However, the overall number of events was still too small to rule out the possibility of a clinically important increase or decrease in serious adverse events (as reflected in the wide confidence intervals). Peto OR was used for the fatal serious adverse events analysis in view of the presence of trials with no deaths in some of the treatment arms.

A post‐hoc observation was that there was a higher number of discontinuations due to adverse events with SiT (OR 2.85; 95% CI 1.89 to 4.30; moderate quality evidence due to risk of bias), see Analysis 1.5. This finding was attributed by the investigators to patients in the SiT arm who changed from metered‐dose inhaler (MDI) to dry‐powder inhaler devices, and who were not allowed to change their maintenance treatment during the course of the study.

Secondary outcomes
Severe exacerbations requiring medical intervention

There was no overall significant reduction in the time to a severe exacerbation, as defined by the investigators, which was the primary outcome measure for these trials (Hazard Ratio (HR) 0.94; 95% CI 0.85 to 1.04, seven studies, N = 7355), Analysis 1.6. The HR was not reported for DE‐SOLO.

Change in morning peak expiratory flow (PEF)

The change in morning PEF (% predicted) in SOLO was 1.00% (95% CI ‐0.96 to 2.96) which was in favour of SiT, but neither clinically nor statistically significant (Analysis 1.7). Data were not available for this outcome from MONO and SALTO.

Rescue medication use

There was a difference of ‐0.16 (95% CI ‐0.27 to ‐0.05) puffs per day of rescue medication use in the SiT arm of SOLO compared to current best practice, Analysis 1.8.

Quality of life (change in ACQ score)

The five studies reporting this outcome had heterogeneous findings (Analysis 1.9). SALTO, SPAIN and SYMPHONIE demonstrated an improvement in the ACQ score in favour of SiT, whilst in DE‐SOLO and SOLO the direction of effect favoured current best practice. The results have not been combined in view of the heterogeneity (I2 = 68%) .

Steroid load

Five studies demonstrated a significantly lower intake of inhaled steroids in the SiT arms in comparison with current best practice but again, heterogeneity was high (I2 = 91%) and the results were therefore not combined. It is expected that the size of the reduction in ICS dose will reflect the trial design for each study, giving rise to the heterogeneity, and in the mean differences that ranged from 107 µg/day in SALTO to 267 µg/day in SOLO (Analysis 1.10). Data from SYMPHONIE indicates a mean difference of 549 µg/day, but this trial has not been reported in full and it is not clear whether this difference includes the inhaled steroid used "as required" in each arm. STYLE also indicated a lower mean daily dose of ICS on SiT (472 versus 516 µg) but provides no variance data in the web report. Furthermore, some trials reported the differences as BDP equivalent doses (e.g. SPAIN); this was not combined with the other trial results.

Adults treated with 80/4.5 µg single inhaler therapy (SiT) (two doses in the evening and as‐needed) versus current best practice

One trial on 102 adults was included for this comparison (Riemersma (NCT00235911). The primary aim of the study was to assess bronchial hyper responsiveness in primary care in adults with mild to moderate persistent asthma who were well controlled on ICS (Analysis 2.6).

The daily average dose of ICS was lower on the SiT arm (326 µg/day in comparison to 798 µg/day on usual care), but the number of participants with exacerbations and adverse events was too small to assess whether the treatments were equivalent or different for the primary outcomes of this review (Analysis 2.1; Analysis 2.2; Analysis 2.3; Analysis 2.4; Analysis 2.5).

Adults and adolescents treated with single inhaler therapy (SiT) versus maintenance inhaled corticosteroids (ICS)with separate reliever inhaler

We have presented the quality of evidence for relevant outcomes in summary of findings Table 2.

Primary outcomes
Exacerbations of asthma causing hospital admissions

Scicchitano 2004, STAY ‐ Adults and STEAM contributed 4209 participants to this outcome, and overall there were fewer admissions on SiT in comparison to ICS, but this was not statistically significant. The number of admitted patients was small (12 in total on SiT and 22 on ICS) and the pooled result is (Peto OR 0.56; 95% CI 0.28 to 1.09; moderate quality evidence due to imprecision), as shown in Figure 5.


Forest plot of comparison: 2 Adults and Adolescents treated with Single Inhaler Therapy versus higher fixed dose ICS, outcome: 2.1 Patients with exacerbations causing hospitalisation.

Forest plot of comparison: 2 Adults and Adolescents treated with Single Inhaler Therapy versus higher fixed dose ICS, outcome: 2.1 Patients with exacerbations causing hospitalisation.

The data used for Scicchitano 2004 and STEAM were on file from AstraZeneca, and were reported as patients with at least one asthma‐aggravated serious adverse event that required hospitalisation. The composite outcome of hospitalisation or ED visits was dominated by participants attending ED and was therefore not used for this outcome. In total,17 patients were admitted to hospital in comparison to 38 seen in ED from these two studies. Peto OR was chosen for this meta‐analysis as this method does not require a continuity correction for zero cells. Sensitivity analysis using Mantel‐Haenszel OR gave very similar results (OR 0.56; 95% CI 0.28 to 1.11).

Exacerbations of asthma treated with oral corticosteroids

Scicchitano 2004, Sovani 2008, STAY ‐ Adults and STEAM contributed data on this outcome from 4280 participants; unpublished data on file from AstraZeneca has been obtained from Scicchitano 2004 and STAY ‐ Adults. The STAY ‐ Adults paper reported descriptive statistics only of courses of oral steroids per year, and in adults this was 0.19 on SiT and 0.38 on budesonide. The pooled result showed a significant reduction in the number of patients requiring a course of steroids (OR 0.54; 95% CI 0.45 to 0.64; high quality evidence) and with a total of 228 patients with an event on SiT and 387 on budesonide, Figure 6. For every 100 adults treated with ICS over 11 months, 18 required a course of oral steroids, whilst for SiT there would be 11 (95% CI: 9 to 12), Figure 7. This translates into a number needed to treat to prevent one patient needing oral corticosteroids over an 11‐month period of 14 (95% CI 12 to 18).


Forest plot of comparison: 2 adults and adolescents treated with Single Inhaler Therapy versus higher fixed dose ICS, outcome: 2.2 Patients with exacerbations treated with oral steroids.

Forest plot of comparison: 2 adults and adolescents treated with Single Inhaler Therapy versus higher fixed dose ICS, outcome: 2.2 Patients with exacerbations treated with oral steroids.


In the fixed dose ICS group 18 people out of 100 had exacerbation treated with oral steroids over 11 months, compared to 11 (95% CI 9 to 12) out of 100 treated with single inhaler therapy. NNT(B) = 14, (95% CI 12 to 18).

In the fixed dose ICS group 18 people out of 100 had exacerbation treated with oral steroids over 11 months, compared to 11 (95% CI 9 to 12) out of 100 treated with single inhaler therapy. NNT(B) = 14, (95% CI 12 to 18).

Sensitivity analysis using random‐effects Mantel‐Haenszel OR gave a marginally wider confidence interval (OR 0.54; 95% CI 0.44 to 0.65). The design of Sovani 2008 was different from the other studies in that adherence with ICSwas the primary concern of the study.

Serious adverse events

No significant difference was seen in either fatal or non‐fatal serious adverse events from the combined results of Scicchitano 2004, STAY ‐ Adults and STEAM; for fatal events (Peto OR 0.37; 95% CI 0.05 to 2.62; moderate quality evidence due to imprecision), and for non‐fatal events (OR 0.97; 95% CI 0.73 to 1.29; moderate quality evidence due to imprecision). Again, the number of events was small (four fatal and 201 non‐fatal) so the confidence interval includes the possibility of important increase or decrease with SiT.

In contrast to the studies comparing SiT to current best practice, a post hoc inspection of discontinuations due to adverse events in Scicchitano 2004 and STEAM found a significant decrease in favour of SiT (OR 0.57; 95% CI 0.35 to 0.93; high quality evidence).

Secondary outcomes
Severe exacerbations requiring medical intervention

There were 1301 on SiT compared with 1285 on twice the dose of budesonide in Scicchitano 2004 and STEAM. There was a significant reduction in the time to a serious exacerbation, as defined by the investigators, (HR 0.59; 95% CI 0.49 to 0.70), Analysis 3.6.

Change in morning peak expiratory flow (PEF) and clinic FEV1

There was a significant increase in PEF in the SiT arms of Scicchitano 2004, STAY ‐ Adults and STEAM compared to higher doses of budesonide (mean difference (MD) 22.29 L/min; 95% CI 17.62 to 26.95), Analysis 3.7. Similarly, an increase of FEV1 in favour of SiT was found (MD 0.10 L ; 95% CI 0.07 to 0.13), Analysis 3.8.

Rescue medication use

There was a reduction in rescue medication use in favour of SiT (MD ‐0.37 puffs per day; 95% CI ‐0.49 to ‐0.25), Analysis 3.9.

Quality of life (change in ACQ score)

The only study reporting ACQ scores was Sovani 2008 and no significant difference was found, Analysis 3.10.

Steroid load

Scicchitano 2004 reported a mean daily budesonide dose of 466 µg/day in the SiT arm in comparison with 640 µg/day in the ICS arm, and 1776 days on oral corticosteroids in comparison with 3177 days. STAY ‐ Adults did not report the mean daily doses of budesonide, but reported 0.19 courses of oral corticosteroids per year for SiT compared to 0.38 per year for higher dose budesonide. STEAM reported a mean daily budesonide dose of 240 µg/day with SiT and 320 µg/day in the higher dose ICS arm. However, the paper also reported five patients on SiT who had a mean daily dose of > 640 µg/day on SiT. Again, STEAM reported a total of 114 days of oral corticosteroids with SiT and 498 days with higher dose budesonide.

Sovani 2008 was designed to investigate whether SiT could overcome poor adherence with ICS, and found an increase in mean daily use of budesonide (448 versus 252 µg/day, MD 196 µg/day, 95% CI 113 to 279 µg/day).

Children treated with single inhaler therapy (SiT) versus higher doses of inhaled corticosteroids (ICS)

Primary outcomes
Exacerbations of asthma causing hospital admissions

We obtained clarification from the sponsors in relation to the hospitalisations for children in each treatment arm of STAY ‐ Children. Hospitalisations related to asthma were reported as none on SiT and one with ICS (this does not quite match the asthma serious adverse event data, as one child was already in hospital with laryngitis, and the stay was prolonged due to an asthma exacerbation) Analysis 4.1. These events were too few to draw any conclusions.

Exacerbations of asthma treated with oral corticosteroids

The only information in the report of STAY ‐ Children in relation to oral corticosteroid use relates to the total number of treatment days in each group (32 days for SiT and 141 days for ICS). This is not suitable for use in meta‐analysis as there is no report of how many children were treated with oral corticosteroids in each group. The sponsors have not been able to provide these data.

Serious adverse events

There were no fatal serious adverse events in STAY ‐ Children and non‐fatal events occurred in two out of 118 children on SiT compared with five out of 106 on ICS (a non‐significant reduction) Analysis 4.3.

Annual height gain

The mean increase in height over one year in the SiT group was 5.3 cm (range 1 to 14 cm) and in the ICS group the mean increase was 4.3 cm (range ‐2 to 15 cm). The fact that some children appear to have become shorter raises concerns about the accuracy of the measurements carried out in some of the 246 centres (as the paper reports that local procedures were used to measure height), but the average advantage of 1 cm for SiT was statistically significant (95% CI 0.3 to 1.7 cms) Analysis 4.4.

Secondary outcomes
Severe exacerbations requiring medical intervention

There were nine patients on SiT with exacerbations requiring medical intervention (hospitalisation or ER visit or course of oral steroids) which was significantly less than the 21 patients given ICS, (OR 0.33; 95% CI 0.15 to 0.77).

Change in morning peak expiratory flow (PEF)

The children given SiT therapy in STAY ‐ Children had an average increase in morning PEF of 12 L/min (95% CI 4.55 to 19.45) in comparison with those given ICS.

Clinic spirometry (FEV1)

There was no significant difference in FEV1 between the SiT and ICS groups in STAY ‐ Children (0.10 L; 95% CI ‐0.14 to 0.34).

Nocturnal awakenings

There were, on average, two less nocturnal awakenings per night for children on SiT than those on ICS in STAY ‐ Children (‐2.00 [95% CI ‐3.33 to ‐0.67]).

Steroid load

The mean daily dose of budesonide in children given SiT in STAY ‐ Children was 126 µg/day in comparison to 320 µg/day in the group randomised to fixed dose budesonide. There were also less days spent on oral corticosteroids in the SiT group (32 versus 141 days). Two of 51 children given SiT had abnormally low cortisol levels in comparison with three of 41 on ICS, a non‐significant reduction (OR 0.52; 95% CI 0.08 to 3.25).

Discussion

Summary of main results

In comparison to current best practice, which allowed the use of long‐acting beta2‐agonists (LABA) in the control arms, the updated evidence from eight trials on 841 adults and adolescents has not demonstrated significant advantages for SiT in exacerbations needing hospital admission (Peto OR 0.81; 95% CI 0.45 to 1.44), but has shown a significant reduction in exacerbations treated with a course of oral steroids (OR 0.83; 95% CI 0.70 to 0.98). For every 100 adults treated with current best practice over six months, seven required a course of oral steroids, whilst for SiT there would be six (95% CI 5 to 7), Figure 4. There was no significant difference found in fatal or non‐fatal serious adverse events, nor in the hazard ratio (HR) of time to first exacerbation (HR 0.94; 95% CI 0.85 to 1.04). All the studies found a reduction in ICS dose when using SiT.

In comparison to higher maintenance doses of budesonide (with no LABA in the control arms), four studies (Scicchitano 2004, STAY ‐ Adults, STEAM and Sovani 2008) involving 4280 patients demonstrated significant reductions in patients with an exacerbation needing oral steroids (OR 0.54; 95% CI 0.45 to 0.64). For every 100 adults treated with inhaled corticosteroids (ICS) over 11 months, 18 required a course of oral steroids, whilst for SiT there would be 11 (95% CI 9 to 12), Figure 7. There was no significant reduction in exacerbations leading to hospitalisation (Peto OR 0.56; 95% CI 0.28 to 1.09). There was no significant difference found in fatal or non‐fatal serious adverse events. The studies also found a reduction in ICS dose when using SiT.

Sovani 2008 demonstrated increased adherence with ICS using SiT in comparison to maintenance budesonide at the same dose.

Only one study included 224 children (STAY ‐ Children) and compared SiT to four times the dose of regular budesonide. There was a significant reduction in exacerbations needing increase in inhaled steroid treatment, or additional treatment or both in this study, but there were only two hospitalised patients and no separate data on courses of oral corticosteroids. There was no significant difference found in fatal or non‐fatal serious adverse events. Less inhaled and oral corticosteroids were used in the SiT group and the annual height gain was also greater in the SiT group.

Overall completeness and applicability of evidence

We found very little evidence in relation to the safety or efficacy of SiT in children, in whom the use of LABA is more contentious (Bisgaard 2003). There is also no separate reporting of results from adolescents in any of the trials of adults and adolescents.

It is possible that the difference between the results in trials comparing SiT with current best practice as opposed to higher doses of ICS alone as a comparison arm could relate to the design of the trials. Around 80% of the patients in the control arm of the current best practice trials were taking LABA, whereas none of the control arm patients in the higher dose maintenance ICS were taking LABA (as they were withdrawn from those patients previously using them). Further information will also be available in the review comparing SiT with combination therapy in double‐blind randomised trials (Cates 2011)

The inclusion of patients who were symptomatic during run‐in periods in which LABA was withdrawn may favour SiT, as formoterol would be expected to control symptoms more quickly than ICS in Scicchitano 2004, STEAM, STAY ‐ Adults and STAY ‐ Children. The plots of individual patient exacerbations show steeper gradients initially for the budesonide arms of these trials but similar gradients in the two groups towards the end of the study period.

This implies that the current evidence comparing SiT with fixed doses of ICS may only be directly applicable to patients who become symptomatic when maintenance treatment with ICS (with or without LABA) is reduced. How these results should be extrapolated to other groups of patients remains a matter for debate.

Interpretation of the results of the studies comparing SiT with current best practice is not straightforward, as the compliance with ICS in the current best practice groups and the SiT groups was based on self‐reporting in a patient note‐book. The lower dose of ICS prescribed in the SiT arms may, therefore, not reflect the true difference in the ICS doses that were actually taken by the participants.

Quality of the evidence

For key outcomes relating to exacerbations, we regarded the risk of detection bias in studies comparing SiT against best practice to be sufficient to downgrade the quality of evidence. Taken with varying degrees of statistical imprecision, we have downgraded to either low or moderate quality evidence for hospital admissions and steroid‐treated exacerbations. In contrast the blinded design of the studies comparing SiT against higher doses of ICS protected the studies against detection bias in our view. The quality of evidence for a reduction in the exacerbations was therefore higher for this comparison.

Agreements and disagreements with other studies or reviews

A meta‐analysis of six of the trials (DE‐SOLO; MONO; SALTO; SOLO; STYLE; SYMPHONIE) comparing SiT with current best practice was published before the 2013 update of this review and the findings for hospitalisation due to exacerbations, courses of oral steroids and time to first exacerbation were very similar to the findings of the updated review (Demoly 2009).

We agree with the reservations voiced by Lipworth 2008 in his response in the BMJ to the review of single inhaler by Barnes 2007. Lipworth comments that the run‐in for the trials comparing SiT with fixed dose ICS was designed to select patients who became symptomatic when their maintenance treatment was reduced or when LABA were withdrawn. This feature of the trial design may contribute to the improvement in time to first asthma exacerbation on SiT, because the onset of action of higher dose ICS would be expected to be slower, and more patients may therefore have suffered an early exacerbation in the higher dose ICS arm of the trials.

Methodological quality summary: review authors' judgements about each methodological quality item for each included study.
Figuras y tablas -
Figure 1

Methodological quality summary: review authors' judgements about each methodological quality item for each included study.

Forest plot of comparison: 1 Adults and Adolescents treated with Single Inhaler Therapy versus Conventional Best Practice, outcome: 1.1 Patients with exacerbations causing hospitalisation.
Figuras y tablas -
Figure 2

Forest plot of comparison: 1 Adults and Adolescents treated with Single Inhaler Therapy versus Conventional Best Practice, outcome: 1.1 Patients with exacerbations causing hospitalisation.

Forest plot of comparison: 1 adults and adolescents treated with Single Inhaler Therapy versus Conventional Best Practice, outcome: 1.2 Patients with exacerbations treated with oral steroids.
Figuras y tablas -
Figure 3

Forest plot of comparison: 1 adults and adolescents treated with Single Inhaler Therapy versus Conventional Best Practice, outcome: 1.2 Patients with exacerbations treated with oral steroids.

In the current best practice group 7 people out of 100 had exacerbations treated with oral steroids over 6 months, compared to 6 (95% CI 5 to 7) out of 100 for the single inhaler therapy group. NNT(B) = 90, (95% CI: 51 to 767).
Figuras y tablas -
Figure 4

In the current best practice group 7 people out of 100 had exacerbations treated with oral steroids over 6 months, compared to 6 (95% CI 5 to 7) out of 100 for the single inhaler therapy group. NNT(B) = 90, (95% CI: 51 to 767).

Forest plot of comparison: 2 Adults and Adolescents treated with Single Inhaler Therapy versus higher fixed dose ICS, outcome: 2.1 Patients with exacerbations causing hospitalisation.
Figuras y tablas -
Figure 5

Forest plot of comparison: 2 Adults and Adolescents treated with Single Inhaler Therapy versus higher fixed dose ICS, outcome: 2.1 Patients with exacerbations causing hospitalisation.

Forest plot of comparison: 2 adults and adolescents treated with Single Inhaler Therapy versus higher fixed dose ICS, outcome: 2.2 Patients with exacerbations treated with oral steroids.
Figuras y tablas -
Figure 6

Forest plot of comparison: 2 adults and adolescents treated with Single Inhaler Therapy versus higher fixed dose ICS, outcome: 2.2 Patients with exacerbations treated with oral steroids.

In the fixed dose ICS group 18 people out of 100 had exacerbation treated with oral steroids over 11 months, compared to 11 (95% CI 9 to 12) out of 100 treated with single inhaler therapy. NNT(B) = 14, (95% CI 12 to 18).
Figuras y tablas -
Figure 7

In the fixed dose ICS group 18 people out of 100 had exacerbation treated with oral steroids over 11 months, compared to 11 (95% CI 9 to 12) out of 100 treated with single inhaler therapy. NNT(B) = 14, (95% CI 12 to 18).

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 1 Patients with exacerbations causing hospitalisation.
Figuras y tablas -
Analysis 1.1

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 1 Patients with exacerbations causing hospitalisation.

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 2 Patients with exacerbations treated with oral steroids.
Figuras y tablas -
Analysis 1.2

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 2 Patients with exacerbations treated with oral steroids.

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 3 Fatal serious adverse events (fatal).
Figuras y tablas -
Analysis 1.3

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 3 Fatal serious adverse events (fatal).

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 4 Serious adverse events (non‐fatal).
Figuras y tablas -
Analysis 1.4

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 4 Serious adverse events (non‐fatal).

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 5 Discontinuation due to adverse events.
Figuras y tablas -
Analysis 1.5

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 5 Discontinuation due to adverse events.

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 6 Patients with "severe" exacerbation (time to event).
Figuras y tablas -
Analysis 1.6

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 6 Patients with "severe" exacerbation (time to event).

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 7 Change in PEF (% predicted).
Figuras y tablas -
Analysis 1.7

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 7 Change in PEF (% predicted).

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 8 Rescue medication use (puffs per day).
Figuras y tablas -
Analysis 1.8

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 8 Rescue medication use (puffs per day).

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 9 Quality of Life (change in ACQ score).
Figuras y tablas -
Analysis 1.9

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 9 Quality of Life (change in ACQ score).

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 10 ICS dose (micrograms per day).
Figuras y tablas -
Analysis 1.10

Comparison 1 Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice, Outcome 10 ICS dose (micrograms per day).

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 1 Patients with exacerbations causing hospitalisation.
Figuras y tablas -
Analysis 2.1

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 1 Patients with exacerbations causing hospitalisation.

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 2 Patients with exacerbations treated with oral steroids.
Figuras y tablas -
Analysis 2.2

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 2 Patients with exacerbations treated with oral steroids.

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 3 Serious adverse events (fatal).
Figuras y tablas -
Analysis 2.3

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 3 Serious adverse events (fatal).

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 4 Serious adverse events (non‐fatal).
Figuras y tablas -
Analysis 2.4

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 4 Serious adverse events (non‐fatal).

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 5 Discontinuation due to adverse events.
Figuras y tablas -
Analysis 2.5

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 5 Discontinuation due to adverse events.

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 6 ICS dose (micrograms per day BDP equivalent).
Figuras y tablas -
Analysis 2.6

Comparison 2 Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care, Outcome 6 ICS dose (micrograms per day BDP equivalent).

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 1 Patients with exacerbations causing hospitalisation.
Figuras y tablas -
Analysis 3.1

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 1 Patients with exacerbations causing hospitalisation.

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 2 Patients with exacerbations treated with oral steroids.
Figuras y tablas -
Analysis 3.2

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 2 Patients with exacerbations treated with oral steroids.

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 3 Fatal serious adverse events.
Figuras y tablas -
Analysis 3.3

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 3 Fatal serious adverse events.

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 4 Serious adverse events (non‐fatal).
Figuras y tablas -
Analysis 3.4

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 4 Serious adverse events (non‐fatal).

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 5 Discontinuation due to adverse events.
Figuras y tablas -
Analysis 3.5

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 5 Discontinuation due to adverse events.

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 6 Patients with "severe" exacerbation (time to event).
Figuras y tablas -
Analysis 3.6

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 6 Patients with "severe" exacerbation (time to event).

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 7 PEF (Litres/min).
Figuras y tablas -
Analysis 3.7

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 7 PEF (Litres/min).

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 8 FEV1 increase (Litres).
Figuras y tablas -
Analysis 3.8

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 8 FEV1 increase (Litres).

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 9 Rescue medication use (puffs per day).
Figuras y tablas -
Analysis 3.9

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 9 Rescue medication use (puffs per day).

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 10 Quality of Life (fall in ACQ score).
Figuras y tablas -
Analysis 3.10

Comparison 3 Adults using BDF single inhaler therapy versus fixed dose ICS, Outcome 10 Quality of Life (fall in ACQ score).

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 1 Patients with exacerbations causing hospitalisation.
Figuras y tablas -
Analysis 4.1

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 1 Patients with exacerbations causing hospitalisation.

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 2 Fatal serious adverse events.
Figuras y tablas -
Analysis 4.2

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 2 Fatal serious adverse events.

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 3 Serious adverse events (non‐fatal).
Figuras y tablas -
Analysis 4.3

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 3 Serious adverse events (non‐fatal).

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 4 Annual height gain (cms).
Figuras y tablas -
Analysis 4.4

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 4 Annual height gain (cms).

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 5 Children with low plasma cortisol (<400 nmol/L).
Figuras y tablas -
Analysis 4.5

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 5 Children with low plasma cortisol (<400 nmol/L).

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 6 Patients with an exacerbation requiring increase in ICS or other treatment.
Figuras y tablas -
Analysis 4.6

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 6 Patients with an exacerbation requiring increase in ICS or other treatment.

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 7 Change in morning PEF (L/min).
Figuras y tablas -
Analysis 4.7

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 7 Change in morning PEF (L/min).

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 8 Change in clinic FEV1 (Litres).
Figuras y tablas -
Analysis 4.8

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 8 Change in clinic FEV1 (Litres).

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 9 As‐needed medication use over 24 hours.
Figuras y tablas -
Analysis 4.9

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 9 As‐needed medication use over 24 hours.

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 10 Nocturnal awakenings.
Figuras y tablas -
Analysis 4.10

Comparison 4 Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS, Outcome 10 Nocturnal awakenings.

Summary of findings for the main comparison. 160/4.5 mcg BDF single inhaler therapy compared to current best practice for adult asthma that is not controlled on ICS

160/4.5 µgBDF single inhaler therapy compared to current best practice for adults with asthma that is not controlled on ICS

Patient or population: adults with asthma that is not controlled on ICS
Settings: community
Intervention: 160/4.5 µg BDF single inhaler therapy
Comparison: current best practice

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Current best practice

160/4.5 µgBDF single inhaler therapy

Patients with exacerbations causing hospitalisation
Follow‐up: mean 6 months

6 per 1000

5 per 1000
(3 to 8)

OR 0.81
(0.45 to 1.44)

8841
(8 studies)

⊕⊕⊝⊝
low1,2

Patients with exacerbations treated with oral steroids
Follow‐up: mean 6 months

70 per 1000

59 per 1000
(50 to 69)

OR 0.83
(0.70 to 0.98)

8841
(8 studies)

⊕⊕⊕⊝
moderate1

Fatal serious adverse events
Follow‐up: mean 6 months

1 per 1000

1 per 1000
(0 to 5)

OR 1.95
(0.53 to 7.21)

8841
(8 studies)

⊕⊕⊝⊝
low1,2

Serious adverse events (non‐fatal)
Follow‐up: mean 6 months

20 per 1000

24 per 1000
(18 to 32)

OR 1.20
(0.90 to 1.60)

8841
(8 studies)

⊕⊕⊝⊝
low1,2

Discontinuation due to adverse events
Follow‐up: mean 6 months

7 per 1000

21 per 1000
(14 to 31)

OR 2.85
(1.89 to 4.3)

8411
(7 studies)

⊕⊕⊕⊝
moderate1

*The basis for the assumed risk is the mean control group risk across studies. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; OR: Odds ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Unblinded trials
2 Confidence interval cannot rule out important differences in either direction

BDF: budesonide plus formoterol; ICS: inhaled corticosteroids

Figuras y tablas -
Summary of findings for the main comparison. 160/4.5 mcg BDF single inhaler therapy compared to current best practice for adult asthma that is not controlled on ICS
Summary of findings 2. Single inhaler therapy compared to fixed dose ICS for asthma in adults not controlled on regular ICS

Single inhaler therapy compared to fixed dose ICS for asthma in adults not controlled on regular ICS

Patient or population: patients with asthma in adults not controlled on regular ICS
Settings: community
Intervention: Single inhaler therapy
Comparison: fixed dose ICS

Outcomes

Illustrative comparative risks* (95% CI)

Relative effect
(95% CI)

No of Participants
(studies)

Quality of the evidence
(GRADE)

Comments

Assumed risk

Corresponding risk

Fixed dose ICS

Single inhaler therapy

Patients with exacerbations causing hospitalisation
Follow‐up: mean 11 months

10 per 1000

6 per 1000
(3 to 11)

OR 0.56
(0.28 to 1.09)

4209
(3 studies)

⊕⊕⊕⊝
moderate1

Patients with exacerbations treated with oral steroids
Follow‐up: mean 11 months

181 per 1000

107 per 1000
(90 to 124)

OR 0.54
(0.45 to 0.64)

4280
(4 studies)

⊕⊕⊕⊕
high

Fatal serious adverse events
Follow‐up: mean 11 months

1 per 1000

1 per 1000
(0 to 4)

OR 0.37
(0.05 to 2.62)

4209
(3 studies)

⊕⊕⊕⊝
moderate1

Serious adverse events (non‐fatal)
Follow‐up: mean 11 months

48 per 1000

47 per 1000
(36 to 62)

OR 0.97
(0.73 to 1.29)

4209
(3 studies)

⊕⊕⊕⊝
moderate1

Discontinuation due to adverse events
Follow‐up: mean 11 months

36 per 1000

21 per 1000
(13 to 33)

OR 0.57
(0.35 to 0.93)

2586
(2 studies)

⊕⊕⊕⊕
high

*The basis for the assumed risk is the mean control group risk across studies. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; OR: Odds ratio;

GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

1 Confidence interval cannot rule out important differences in either direction
ICS: inhaled corticosteroids

Figuras y tablas -
Summary of findings 2. Single inhaler therapy compared to fixed dose ICS for asthma in adults not controlled on regular ICS
Comparison 1. Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Patients with exacerbations causing hospitalisation Show forest plot

8

8841

Peto Odds Ratio (Peto, Fixed, 95% CI)

0.81 [0.45, 1.44]

2 Patients with exacerbations treated with oral steroids Show forest plot

8

8841

Odds Ratio (M‐H, Fixed, 95% CI)

0.83 [0.70, 0.98]

3 Fatal serious adverse events (fatal) Show forest plot

8

8841

Peto Odds Ratio (Peto, Fixed, 95% CI)

1.95 [0.53, 7.21]

4 Serious adverse events (non‐fatal) Show forest plot

8

8839

Odds Ratio (M‐H, Fixed, 95% CI)

1.20 [0.90, 1.60]

5 Discontinuation due to adverse events Show forest plot

7

8411

Odds Ratio (M‐H, Fixed, 95% CI)

2.85 [1.89, 4.30]

6 Patients with "severe" exacerbation (time to event) Show forest plot

7

7355

Hazard Ratio (Fixed, 95% CI)

0.94 [0.85, 1.04]

7 Change in PEF (% predicted) Show forest plot

1

Mean Difference (Fixed, 95% CI)

Subtotals only

8 Rescue medication use (puffs per day) Show forest plot

1

Mean Difference (Fixed, 95% CI)

Subtotals only

9 Quality of Life (change in ACQ score) Show forest plot

5

Mean Difference (Fixed, 95% CI)

Totals not selected

10 ICS dose (micrograms per day) Show forest plot

5

Mean Difference (Fixed, 95% CI)

Totals not selected

10.1 ICS as prescribed

4

Mean Difference (Fixed, 95% CI)

0.0 [0.0, 0.0]

10.2 BDP equivalent doses

1

Mean Difference (Fixed, 95% CI)

0.0 [0.0, 0.0]

Figuras y tablas -
Comparison 1. Adults using 160/4.5 mcg BDF single inhaler therapy versus current best practice
Comparison 2. Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Patients with exacerbations causing hospitalisation Show forest plot

1

102

Peto Odds Ratio (Peto, Fixed, 95% CI)

0.0 [0.0, 0.0]

2 Patients with exacerbations treated with oral steroids Show forest plot

1

Odds Ratio (M‐H, Fixed, 95% CI)

Totals not selected

3 Serious adverse events (fatal) Show forest plot

1

102

Peto Odds Ratio (Peto, Fixed, 95% CI)

0.0 [0.0, 0.0]

4 Serious adverse events (non‐fatal) Show forest plot

1

Odds Ratio (M‐H, Fixed, 95% CI)

Totals not selected

5 Discontinuation due to adverse events Show forest plot

1

Odds Ratio (M‐H, Fixed, 95% CI)

Totals not selected

6 ICS dose (micrograms per day BDP equivalent) Show forest plot

1

Mean Difference (Fixed, 95% CI)

Totals not selected

Figuras y tablas -
Comparison 2. Adults using 80/4.5 mcg BDF single inhaler therapy versus usual care
Comparison 3. Adults using BDF single inhaler therapy versus fixed dose ICS

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Patients with exacerbations causing hospitalisation Show forest plot

3

4209

Peto Odds Ratio (Peto, Fixed, 95% CI)

0.56 [0.28, 1.09]

1.1 Single inhaler therapy versus higher dose ICS

3

4209

Peto Odds Ratio (Peto, Fixed, 95% CI)

0.56 [0.28, 1.09]

2 Patients with exacerbations treated with oral steroids Show forest plot

4

4280

Odds Ratio (M‐H, Fixed, 95% CI)

0.54 [0.45, 0.64]

2.1 Single inhaler therapy versus higher dose ICS

3

4209

Odds Ratio (M‐H, Fixed, 95% CI)

0.53 [0.44, 0.63]

2.2 Single inhaler therapy versus same dose ICS

1

71

Odds Ratio (M‐H, Fixed, 95% CI)

1.42 [0.29, 6.86]

3 Fatal serious adverse events Show forest plot

3

4209

Peto Odds Ratio (Peto, Fixed, 95% CI)

0.37 [0.05, 2.62]

3.1 Single inhaler therapy versus higher dose ICS

3

4209

Peto Odds Ratio (Peto, Fixed, 95% CI)

0.37 [0.05, 2.62]

4 Serious adverse events (non‐fatal) Show forest plot

3

4209

Odds Ratio (M‐H, Fixed, 95% CI)

0.97 [0.73, 1.29]

4.1 Single inhaler therapy versus higher dose ICS

3

4209

Odds Ratio (M‐H, Fixed, 95% CI)

0.97 [0.73, 1.29]

5 Discontinuation due to adverse events Show forest plot

2

2586

Odds Ratio (M‐H, Fixed, 95% CI)

0.57 [0.35, 0.93]

5.1 Single inhaler therapy versus higher dose ICS

2

2586

Odds Ratio (M‐H, Fixed, 95% CI)

0.57 [0.35, 0.93]

6 Patients with "severe" exacerbation (time to event) Show forest plot

2

2586

Hazard Ratio (Fixed, 95% CI)

0.59 [0.49, 0.70]

6.1 Single inhaler therapy versus higher dose ICS

2

2586

Hazard Ratio (Fixed, 95% CI)

0.59 [0.49, 0.70]

7 PEF (Litres/min) Show forest plot

3

Mean Difference (Fixed, 95% CI)

22.29 [17.62, 26.95]

7.1 Single inhaler therapy versus higher dose ICS

3

Mean Difference (Fixed, 95% CI)

22.29 [17.62, 26.95]

8 FEV1 increase (Litres) Show forest plot

3

Mean Difference (Fixed, 95% CI)

0.10 [0.07, 0.13]

8.1 Single inhaler therapy versus higher dose ICS

2

Mean Difference (Fixed, 95% CI)

0.10 [0.08, 0.13]

8.2 Single inhaler therapy versus same dose ICS

1

Mean Difference (Fixed, 95% CI)

0.01 [‐0.19, 0.21]

9 Rescue medication use (puffs per day) Show forest plot

3

Mean Difference (Fixed, 95% CI)

‐0.37 [‐0.49, ‐0.25]

9.1 Single inhaler therapy versus higher dose ICS

3

Mean Difference (Fixed, 95% CI)

‐0.37 [‐0.49, ‐0.25]

10 Quality of Life (fall in ACQ score) Show forest plot

1

Mean Difference (Fixed, 95% CI)

Totals not selected

10.1 Single inhaler therapy versus same dose ICS

1

Mean Difference (Fixed, 95% CI)

0.0 [0.0, 0.0]

Figuras y tablas -
Comparison 3. Adults using BDF single inhaler therapy versus fixed dose ICS
Comparison 4. Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Patients with exacerbations causing hospitalisation Show forest plot

1

Peto Odds Ratio (Peto, Fixed, 95% CI)

Totals not selected

2 Fatal serious adverse events Show forest plot

1

224

Odds Ratio (M‐H, Fixed, 95% CI)

0.0 [0.0, 0.0]

3 Serious adverse events (non‐fatal) Show forest plot

1

Odds Ratio (M‐H, Fixed, 95% CI)

Totals not selected

4 Annual height gain (cms) Show forest plot

1

Mean Difference (IV, Fixed, 95% CI)

Totals not selected

5 Children with low plasma cortisol (<400 nmol/L) Show forest plot

1

Odds Ratio (M‐H, Fixed, 95% CI)

Totals not selected

6 Patients with an exacerbation requiring increase in ICS or other treatment Show forest plot

1

Odds Ratio (M‐H, Fixed, 95% CI)

Totals not selected

7 Change in morning PEF (L/min) Show forest plot

1

Mean Difference (Fixed, 95% CI)

Totals not selected

8 Change in clinic FEV1 (Litres) Show forest plot

1

Mean Difference (Fixed, 95% CI)

Totals not selected

9 As‐needed medication use over 24 hours Show forest plot

1

Mean Difference (Fixed, 95% CI)

Totals not selected

10 Nocturnal awakenings Show forest plot

1

Mean Difference (Fixed, 95% CI)

Totals not selected

Figuras y tablas -
Comparison 4. Children using 80/4.5 mcg BDF single inhaler therapy versus higher fixed dose ICS