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介入措施以提升正在治療癌症或是已經治療完成病患的運動習慣

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背景

規律運動對於罹癌病人或是已經治療完成的癌症病患會帶來有益效益越來越顯而易見。然而,如何去提倡運動的行為對於久坐的癌症族群還不是有很清楚。多數正在接受治療的癌症病患或是從癌症中康復的病患,並沒有運動的建議。因此,回顧證據如何去提倡或是維持運動行為是相當重要的。

目的

對於正在治療或是已經治療完成的久坐病患,提倡運動行為,評估介入措施的有效性,並處理正在治療或是治療過後的癌症病患以下的問題:哪一個介入措施能最有效的改善有氧運動和肌肉骨骼的強度、耐受性?不同的運動介入措施會有什麼樣的不良反應?對於不同的癌症病患,哪一個介入措施能最有效的改善運動行為?哪一個介入措施最有可能可以維持長達12個月或是更長的運動習慣?與專業的運動訓練員接觸的頻繁度是否和增加運動行為有所關連?什麼樣的理論基礎是和增加運動行為最有關聯?什麼樣的行為改變和增加運動行為是最有關聯?

搜尋策略

我們搜尋以下的電子資料庫:Cochrane Central Register of Controlled Trials (CENTRAL,The Cochrane Library,第8期, 2012), MEDLINE, EMBASE, AMED, CINAHL, PsycLIT/PsycINFO, SportDiscus and PEDro 從創立到2012年8月的資料。我們同時間也搜尋灰色文獻、寫信給該領域的專家及財團法人,或是搜尋參考文獻清單中近期的系統性文獻回顧。

選擇標準

我們只納入針對被診斷出有原發性癌症且年齡18歲以上、經常久坐的病患,將介入運動措施與常規照護比較之隨機對照實驗。

資料收集與分析

二位作者(LB and KH)獨立作業,包含篩選所有蒐尋文獻之標題和摘要以確認該研究是否符合納入準則,或是由於尚未完整評估全文(如:沒有提供摘要的文獻)因此無法安全地排除。所有符合納入準則的文章至少會經由作者團隊中其中2位作者(LB and KH)獨立地萃取資料,並使用資料收集的格式進行萃取。如果可行,或者為適當的,我們會將研究結果用固定效應(fixed‐effect) 的統合分析方式呈現。對於連續性結果(像是:心肺功能運動),我們萃取最終數值、感興趣結果的標準偏差及每個治療端追蹤評估的參與者人數,以估計治療端間的標準平均差(SMD)。SMD被研究員使用於不同種類的方法來評估個人的結果。如果統合分析是不可能的或者是不恰當的,我們將以敘述整合研究結果。

主要結果

這一個回顧中納入了14個試驗,共648位參與者。只有包含乳癌、攝護腺癌或是大腸癌的研究被評斷符合納入準則。當中只有6個研究有符合現今運動建議的目標量。只有三個試驗中,明確客觀地驗證自主運動行為並有加速器及心律的監測。遵從運動介入措施,對於了解治療的劑量是相當重要的,往往沒有受到重視。基本的運動指標需要特別被重視(即頻率、強度和持續時間,重複,組套和阻力訓練的強度),雖然容易設計和被報告,但卻很少被臨床試驗所公布。

沒有一個試驗報告表示,任何後續追蹤中,有75%或更高地遵從性有符合現今的有氧運動建議(這次文獻回顧的主要結果)。只有兩個試驗報告,執行6週的阻力運動有符合指引的建議。然而,三個試驗報告顯示,對於有氧運動的目標有75%的遵從或更高,但其少於現今運動指引所建議的每週150分鐘。所有三個合併監測和獨立運動條件以作為介入措施的一部分,在控制組中沒有一項關於運動行為的限制。這三個試驗中有相同的設定目標和以下行為改變的技巧:目標行為的推廣、提升自我監測的行為並促使運動。儘管許多納入的試驗當中,環繞著的不確定性地遵從性,從8〜12週的參與介入措施和控制組相,其有氧運動耐受力有獲改善(7個研究中,標準平均差 0.73,95%信賴區間0.51〜0.95)。在6個月的計畫中,有氧運動耐受性也有所改善(5個研究中,標準平均差0.70,95%信賴區間 0.45˜0.94),但應注意的是,在分析當中,5個試驗中有4個有高風險的偏差,因此,在解釋結果時,需再加以警示。這些介入過程中的流失率通常很低(中位數為6%)。

作者結論

對於癌症存活者(被報告有更高地遵從性)以介入措施促進運動並分享普遍行為改變的方式。這涉及制定計劃目標、提升實踐力、自我監控,和鼓勵參加者,試圖推廣行為學習,不論是否有監督環境或是其他無監管環境。然而,期待久坐的存活者,達到現今有氧運動所指引的每週至少150分鐘是很難實現的。如同所有設計良好的運動計畫,設計者應視個人的能力來設計其運動的頻率、持續時間、強度、套餐或是重複性,強度或阻力訓練應該建議在以上的基礎上。

PICOs

Population
Intervention
Comparison
Outcome

The PICO model is widely used and taught in evidence-based health care as a strategy for formulating questions and search strategies and for characterizing clinical studies or meta-analyses. PICO stands for four different potential components of a clinical question: Patient, Population or Problem; Intervention; Comparison; Outcome.

See more on using PICO in the Cochrane Handbook.

Plain language summary

標題:介入措施以提升正在治療癌症或是已經治癒病患的運動習慣

文獻回顧問題對於正在治療或是已經治療完成的癌症病患而言,什麼是最有效的方式以改善和維持運動的行為?

背景:對一個正在治療或是已經治療完成的癌症病患而言,規律的身體活動,有多方的益處。其益處範圍包含提高生活質量進而改善身體機能,也可減少癌症復發的風險和因癌症死亡的風險。我們知道,大多數人罹患或是已經治療完成的癌症病患大多沒有規律的運動。因此,我們需要了解如何讓這些人開始有運動的習慣,以及如何幫助他們保持這種行為的改變。

研究特點:我們只納入有常規介入運動措施的研究。參與者是隨機被選取到任一組別。我們搜尋證據從研究開始的時間回溯到2012年8月。納入習慣久坐且具有相同的癌症診斷之年滿18歲以上參與者之研究才符合納入條件。參與者是隨機被分派到任一組別。我們從研究資料庫搜索到2012年8月的證據。

主要結果:此次文獻回顧共納入14個試驗,648位參與者。證據顯示,我們缺乏了解該如何鼓勵正在接受治療或是已經治療完成的癌症病患,達到現今的運動建議量。進一步的來說,研究人員報導試驗中的運動程序及有多少的參與者等,是不夠詳盡的。然而,我們確實發現一些證據表示,制訂運動目標、推動人們運動、促使人們監督自己的行為及讓人們思考如何在沒有監督的情況下運動可能會有所幫助。此外,我們還發現了一些證據表示,研究參與者能更好地耐受長達六個月的運動鍛煉。

證據的品質:我們發現在此文獻回顧與研究品質有關最主要的問題包含有,不知道如何將受試者隨機化的分配在試驗中,以及是否此試驗的研究人員知道哪一個受試者被隨機分配到哪一個組別中。

Authors' conclusions

Implications for practice

Service provision to promote exercise in sedentary people living with and beyond cancer should incorporate components of both supervised and independent exercise requirements. Setting programme goals, prompting practise and self‐monitoring, and encouraging people to attempt to generalise behaviour learned in supervised exercise environments to other non‐supervised contexts are common components of interventions that report meaningful adherence. However, expecting most sedentary survivors to achieve at least 150 minutes per week of aerobic exercise is likely to be unrealistic. As with all well‐designed exercise programmes in any context, prescriptions should be designed around individual capabilities and frequency, duration and intensity or sets, repetitions and intensity, or resistance training should be generated on this basis. Using these essential metrics of exercise prescription not only will help achieve a balance between safe yet effective exercise, but also will ensure that meaningful re‐evaluation over time can be undertaken, as adaptation or disease progression dictates. Relevant training in exercise prescription for people living with and beyond cancer can be undertaken through established reputable bodies such as the American College of Sports Medicine, which runs courses in collaboration with the American Cancer Society.

Implications for research

Recently, in the largest survey of cancer survivors (covering multiple cancer types) to have been conducted in Europe (N = 3300), the UK Department of Health reported that less than 25% of people living with and beyond cancer are achieving 30 minutes of exercise on five or more days per week (Department of Health 2012). This is a clear indicator that an overwhelming majority of cancer survivors are not active. It is therefore of critical importance that:

  • future research is primarily targeted towards a better understanding of effective promotion of exercise behaviour in sedentary individuals living with or beyond cancer;

  • trials are explicit about baseline exercise behaviour and about how it was assessed;

  • all trials report as standard frequency, intensity and duration of aerobic exercise, as well as repetitions, sets and intensity of resistance exercise used in intervention prescriptions;

  • standardisation of adherence reporting is achieved in clinical trials investigating the effects of exercise in cancer survivors. We recommend that adherence is reported as a single proportion of the cohort who attended/performed exercise according to the set prescription;

  • accelerometers do not appear to be a helpful tool for objectively validating exercise behaviour in the trials that we have reviewed. We recommend the use of heart rate monitoring during set, purposeful bouts of exercise; and

  • reporting of behaviour change techniques employed in such interventions is standardised. Adoption of the CALO‐RE taxonomy or the broader BCT v1 taxonomy is recommended.

By achieving these standardisations, oncology scientists and clinicians will help bring the discipline up to the level of acceptable rigor that will elucidate dose response of exercise interventions for given health outcomes. This should afford an opportunity for practitioners to communicate achievable exercise recommendations for sedentary people living with and beyond cancer.

Background

Description of the condition

Approximately 25 million people worldwide are living with cancer (Kamangar 2006). As such, cancer represents one of the largest global health problems. Breast, prostate and bowel cancer account for most of the survivorship population (around 52%) (Maddams 2009). Recent evidence from Macmillan Cancer Support indicates that cancer survival rates have much improved over the past 30 years (Macmillan Cancer Support 2012). Coleman 2011 reported that relative survival has improved in breast, colorectal, lung and ovarian cancer over the period 1995‐2007. This is good news for people living with the more common cancers who are undergoing, or recovering from, treatment. However, this also means that survivors are living longer with the consequences of cancer treatment, which frequently manifest as fatigue, reduced functional capacity and poorer health‐related quality of life (HRQoL). Further, cancer survivors are significantly more likely to report poor health outcomes compared with those with no history of cancer or a chronic condition (Elliott 2011). Throughout this review, we will define a cancer survivor as someone 'living with or beyond cancer', in line with the Macmillan Cancer Support definition (Macmillan Cancer Support 2011).

Description of the intervention

The goal of any exercise regime is a sustained physiological challenge that, over time, will induce a spectrum of beneficial cardiovascular, respiratory, musculoskeletal, neurological and metabolic adaptations. In the context of living with or beyond disease, it is these adaptations that will likely translate to a range of benefits from improvements in HRQoL and physical function to reducing disease progression, secondary recurrence and mortality (Fong 2012; Ibrahim 2011). Evidence for this in cancer populations ranges from epidemiological observations to cause and effect derived from randomised controlled trials (RCTs). As such, the potential for habitual exercise to act as a useful adjunctive therapy is a growing area of research interest (Rock 2012). The UK Chief Medical Officer recommends that in adults, weekly activity should add up to at least 150 minutes of moderate intensity exercise, performed in bouts of 10 minutes or longer (Department of Health 2011; Rock 2012). For example, this could translate to 30 minutes of exercise that raises heart rate and breathing rate, five times per week. Alternatively, 75 minutes of vigorous intensity activity spread across the week can confer similar benefits. The general consensus is that such guidelines are also appropriate for adult cancer survivors (Rock 2012). However, encouraging people to participate in regular exercise from a background of a sedentary lifestyle is difficult, requiring attention to psychosocial and behavioural influences on exercise, as well as the physiological basis of exercise (Greaves 2011). A still greater challenge is to provide a support structure for physical activity until it becomes a pattern of sustained healthy behaviour. In this review, interventions of interest include any programmes that promote increased exercise behaviour in people living with and beyond cancer, with a particular focus on long‐term change in exercise behaviour.

How the intervention might work

RCTs in people living with and beyond cancer have assessed various interventions aimed at promoting both short‐ and long‐term exercise participation. These include approaches such as supervised exercise (Bourke 2011); home‐based exercise (Courneya 2003); group‐based patient education (Carmack Taylor 2006); information leaflets (Demark‐Wahnefried 2007); cognitive behavioural therapy approaches (May 2008) and motivational interviewing (Bennett 2007). Tailored exercise interventions commonly comprise aerobic exercise training, resistance (strength) training or a combination of both, with or without behaviour change support. These approaches tend to vary in the extent to which they are based on behaviour change theory or employ specific behaviour change techniques. 

Why it is important to do this review

A large majority of people living with and beyond cancer are not regularly active (for the purposes of this review, referred to as "sedentary") (Department of Health 2012). Systematic reviews and meta‐analyses of interventions promoting exercise participation in people living with and beyond cancer have reported a range of benefits, including reduced fatigue and improved functional capacity/physical fitness and HRQoL (Cramp 2012; Demark‐Wahnefried 2007; Fong 2012; McNeely 2006; Pekmezi 2011; Mishra 2012a; Mishra 2012b). However, most of the current evidence comes from trials with short‐term interventions and follow‐up, with any benefits likely to be transient if exercise behaviour is not sustained. Understanding which interventions are most efficacious in supporting long‐term exercise behaviour would be very useful (Bourke 2012), not just because of the HRQoL benefits, but emerging observational data suggest that being regularly active can reduce the chances of dying from cancer after diagnosis. Physical activity in observational studies is usually estimated as the self‐reported time spent exercising and is reported as metabolic equivalent task (MET)‐hours per week, using typical MET values for specific activities (Ainsworth 2011). In breast, prostate and bowel cancer, increased post‐diagnosis exercise behaviour has been reported to reduce cancer‐specific mortality risk by 32% to 61%, with around 18 to 27 MET‐hours per week of exercise conferring benefit (Haydon 2006; Holick 2008; Holmes 2005; Kenfield 2011; Meyerhardt 2006; Meyerhardt 2009; Nilsen 2006). Furthermore, providing an understanding of which behaviour change theories and behaviour change techniques are most efficacious in improving exercise behaviour will facilitate optimal design for future exercise interventions.

In the UK, the National Cancer Survivorship Initiative has highlighted physical symptoms as a consequence of treatment as an area of research with the highest priority (Richards 2011). Furthermore, from an international perspective, the recent Lancet Oncology Commission called for novel, more effective and less toxic interventions for delivering affordable cancer care (Sullivan 2011). Promoting habitual exercise participation could satisfy both of these high priority agendas.

We have deliberately chosen the term “habitual” over “regular” to reflect the intention to assess which interventions could improve and sustain exercise behaviour. “Regular exercise” can be applied to both short‐term and long‐term contexts, where as a “habitual” exerciser indicates a sustained and regular pattern of behaviour. Furthermore, “habitual” refers to the process of behavioural “habit forming”, which suggests an automaticity of behaviour, thereby improving maintenance of behaviour change (Gardner 2011; Verplanken and Melkelvik 2009). Systematically reviewing variations in frequency, intensity and duration of exercise achieved, the theoretical basis of the intervention and behaviour change techniques used, adherence to these interventions, attrition, reported adverse events and duration of sustained meaningful exercise behaviour is crucial for informing future trial design (in under‐studied cancer populations) and for facilitating the integration of exercise therapy into existing care pathways (when the evidence demonstrates efficacy for a given intervention). The purpose of this review is to summarise the existing literature on the effects of exercise‐promoting interventions on short‐ and longer‐term exercise behaviour in previously sedentary people living with and beyond cancer.

Objectives

Primary objective

To assess the effects of interventions to promote exercise behaviour in sedentary people living with and beyond cancer

Secondary objectives

To address the following questions:

  • Which interventions are most effective in improving aerobic fitness and skeletal muscle strength and endurance?

  • What adverse effects are attributed to different exercise interventions?

  • Which interventions are most effective in improving exercise behaviour amongst patients with different cancers?

  • Which interventions are most likely to promote long‐term (12 months or longer) exercise behaviour?

  • What frequency of contact with exercise professionals is associated with increased exercise behaviour?

  • What theoretical basis is most often associated with increased exercise behaviour?

  • What behaviour change techniques are most often associated with increased exercise behaviour?

Methods

Criteria for considering studies for this review

Types of studies

RCTs that allocated participants or clusters of participants by a random method to an exercise‐promoting intervention compared with usual care or 'waiting list' control. We included only RCTs that aimed to improve exercise behaviour compared with a usual care comparison group. We included studies conducted both during and after primary treatment or during active monitoring. Only interventions that included a component targeted at increasing aerobic exercise and/or resistance exercise behaviour will be included in this review. We did not include studies of heterogeneous cancer cohorts (i.e. participants with different primary cancer sites). We did not include studies in 'at risk' populations (i.e. studies involving individuals who have risk factors for cancer but who have not yet been diagnosed with the disease) that addressed primary prevention research questions.

Types of participants

We included only trials involving adults (18 years of age or older) who had a sedentary lifestyle at baseline (i.e. not undertaking 30 minutes or more of exercise of at least moderate intensity, three days per week, or 90 minutes in total of moderate intensity exercise per week). Participants must have been histologically or clinically diagnosed with cancer regardless of sex, tumour site, tumour type, tumour stage and type of anticancer treatment received. We excluded trials directed specifically at end‐of‐life‐care patients and individuals who were currently hospital inpatients.

Types of interventions

For the purposes of this review, the phrases 'exercise' and 'physical activity' were used interchangeably. Definitions of exercise, related terms and nomenclature that describe the performance of exercise must adhere to principles of science and must satisfy the Système International d'Unités (SI), which was adopted universally in 1960. Hence, we referred to the appropriate, combined definition that applies to all situations: "A potential disruption to homeostasis by muscle activity that is either exclusively or in combination, concentric, eccentric or isometric" (Winter and Fowler 2009). Investigators must have reported frequency, duration and intensity of aerobic exercise behaviour or frequency, intensity, type, sets, repetitions and pattern of resistance of exercise behaviour that was prescribed in the intervention.

We acknowledge that the maximal aerobic capacity (VO2max)/peak is often the most informative metric for setting aerobic exercise intensity; however, given the nature of the population involved (elderly, potentially with multiple co‐morbidities), it is often difficult to conduct maximal testing protocols to prescribe intensity on the basis of these measures because of the requirements for medically qualified staff to be present during assessment. As such, for reasons of pragmatism, we accept that exercise intensity is more frequently reported in the cohorts in terms of age‐predicted maximum heart rate max (HRmax) or on the Borg rating of perceived exertion (RPE) scale (Borg 1982). The interventions in this review were categorised as achieving a mild (less than 60% HRmax/10 RPE or less), moderate (60% to 84% HRmax/11 to 14 RPE) or vigorous (85% HRmax or more/15 RPE or more) exercise intensity.

Types of outcome measures

Primary outcomes

Aerobic exercise behaviour as measured by: 

  • exercise frequency (number of bouts per week);

  • exercise duration (total minutes of exercise achieved);

  • exercise intensity (e.g. % HRmax, RPE);

  • estimated energy expenditure from free living physical activity (e.g. from accelerometer readings [where available]);

  • adherence to the exercise intervention (% of exercise sessions completed/attended);

  • total duration of intervention when ≥75% adherence is achieved (in weeks); and

  • total duration of sustained exercise behaviour meeting American Cancer Society guidelines for exercise in people living with and beyond cancer (Rock 2012; i.e. aim to exercise at least 150 minutes per week, with at least two days per week of strength training).

Resistance exercise behaviour as measured by:

  • exercise frequency (number of bouts per week);

  • exercise intensity (e.g. % of 1 repetition max or % of body mass);

  • type of exercise (e.g. free weights, body weight exercise);

  • repetitions;

  • sets; and

  • pattern (quantification of rest period in relation to sets and repetitions).

Secondary outcomes

  • Change in aerobic fitness or exercise tolerance (maximal or submaximal when measured directly or by a standard field test).

  • Change in skeletal muscle strength and endurance.

  • Adverse effects.

  • Trial recruitment rate.  

  • Intervention attrition rate.

Interventions were judged as successful in achieving exercise goals as identified in the study methods if investigators reported at least 75% adherence over a given follow‐up period. Data on compliance with the intervention were quantified in terms of number of prescribed exercise sessions completed as a proportion of the total set. The intervention must have included at least 6 weeks of follow‐up. Interventions were categorised according to whether they were based on a behaviour change theory (e.g. control theory, social cognitive theory; Bandura 2000; Bandura 2002; Carver 1982). This relates to the National Institute for Health and Clinical Excellence (NICE) guidance for behaviour change, which recommends that clinicians should be explicit about the theoretical constructs on which interventions are based (NICE 2007). Interventions were also categorised using the ‘Coventry, Aberdeen & London-Refined’ (CALO‐RE) taxonomy (Michie 2011). This is a validated taxonomy of behaviour change techniques (BCTs) that can be used to help people change their exercise behaviour. Categorising interventions according to this taxonomy resulted in a better understanding of which techniques are employed by current interventions and how they are related to short‐ and longer‐term exercise behaviour change.

Search methods for identification of studies

Electronic searches

We searched the following electronic databases.

  • CENTRAL (Cochrane Central Register of Controlled Trials).

  • MEDLINE (Medical Literature Analysis and Retrieval System Online).

  • EMBASE (the Excerpta Medica database).

  • AMED (Allied and Alternative Medicine Database; covers occupational therapy, physiotherapy and complementary medicine).

  • CINAHL (Cumulative Index to Nursing and Allied Health Literature).

  • PsycINFO (Database of the American Psychological Association).

  • SportDiscus (Sports Evidence Database).

  • PEDro (Physiotherapy Evidence Database).

The MEDLINE search strategy is presented in Appendix 2. For databases other than MEDLINE, we adapted the search strategy accordingly: EMBASE (Appendix 3), AMED (Appendix 4), CINAHL (Appendix 5) and PsycINFO (Appendix 6).

The search strategies were developed with the Cochrane Gynaecological Cancer Group Information Manager (Jane Hayes) and included MeSH and text word terms as appropriate.

We attempted to identify all relevant articles on PubMed, using the 'related articles' feature, and performed further searches for newly published articles.

Searching other resources

We searched reference lists of retrieved articles and published reviews on the topic. We contacted the principal investigators of the identified studies, as well as 10 national and international experts in the field, to ask whether they were aware of any other relevant unpublished studies in the area.

We expanded the database search by identifying additional relevant studies for this review, including unpublished studies and references in the grey literature. This was done by searching the OpenGrey database (http://www.opengrey.eu/), which includes technical or research reports, doctoral dissertations, conference papers and other types of grey literature. We also searched the following clinical trials web pages:  

We screened the full text of any relevant papers identified through these searches. We also approached the principal investigators and major co‐operative groups active in this area to ask for relevant data. Furthermore, we wrote to Cancer Research UK (CRUK), Macmillan Cancer Support, the World Cancer Research Fund (WCRF), the Association for International Cancer Research (AICR), the American Association for Cancer Research (AACR), the American Cancer Society (ACS) and the American Society of Clinical Oncology (ASCO) to enquire about relevant unpublished papers.

Data collection and analysis

Selection of studies

We imported results from each database into the reference management software package Endnote, from which we removed duplicates and selected relevant articles for screening. After training on the first 100 references retrieved from two different databases was provided to ensure a consistent approach, two review authors (LB and KH) worked independently to screen all titles and abstracts to identify studies that met the inclusion criteria, or that could not be safely excluded without assessment of the full text (e.g. when no abstract was available). Disagreements were resolved by discussion with another review author (ST or DR). Full texts were retrieved for these articles. 

After training was provided to ensure a consistent approach to study assessment and data abstraction, two review authors worked independently to assess the retrieved full texts. We linked together multiple publications and reports on the same study. Studies that appeared to be relevant but are excluded at this stage were listed in the 'Characteristics of excluded studies' table. We resolved disagreements by discussion with other group members. We attempted to contact study corresponding authors if we could not access a full text (e.g. if only an abstract was available), if we required more information to determine whether a study could be included (e.g. to determine baseline exercise behaviour of a cohort) or if we required supplementary information about an already eligible trial (please also see Excluded studies).

Data extraction and management

We extracted the following data.

  • Study details: author, year, research question/study aim; country where the research was carried out; recruitment source (e.g. consecutive sampling from outpatient appointments; advertising in the community; convenient sample from support groups); inclusion and exclusion criteria; study design (cluster RCT, non‐cluster RCT, single centre or multi‐centre); length of follow‐up; description of usual care.

  • Intervention details: categorisation of intervention (e.g. supervised, independent, educational); setting (e.g. dedicated exercise facility, community, home); exercise prescription components (e.g. aerobic exercise, resistance exercise, stretching); theoretical basis, behaviour change techniques (using CALO‐RE taxonomy), frequency of contact with an exercise professional.

  • Participant characteristics: primary cancer diagnosis; any cancer treatment currently undertaken; metastatic disease status; age; sex; socio‐economic status; ethnicity; reported comorbidities. 

  • Resulting exercise behaviour: method of measuring exercise (e.g. self‐report questionnaire). Numbers of participants randomly assigned and assessed at specified follow‐up points. Frequency, duration, intensity of aerobic exercise achieved; frequency, intensity, type, sets, repetitions and pattern of resistance exercise achieved; total duration of the intervention and total duration of sustained meaningful exercise behaviour as a result of the intervention. Adherence to the intervention; rate of attrition and adverse effects reported.

  • Resulting change in other outcomes: changes in aerobic fitness and estimated energy expenditure from free living physical activity.

Two members of the group worked independently (LB and KH) to abstract data from all eligible papers using the data collection form. Data were to be entered into the Cochrane Collaboration's statistical software, Review Manager 2011, by one review author and checked by a second review author.

Assessment of risk of bias in included studies

Risk of bias and methodological quality were assessed in accordance with the Cochrane Collaboration's tool for assessing risk of bias (Higgins 2011). The tool includes the following seven domains:

  • sequence generation (method of randomisation);

  • allocation concealment (selection bias);

  • blinding (masking) of participants and personnel (detections bias);

  • blinding (masking) of outcome assessors (detection bias);

  • incomplete outcome data;

  • selective outcome reporting; and

  • other sources of bias.

However, we did not include whether participants were blind to their allocation of intervention or to control groups, as it is often not possible (e.g. in a supervised exercise setting) to blind participants to an intervention while promoting exercise behaviour. Two review authors (LB and KH) applied the risk of bias tool independently, and differences were resolved by discussion with a third review author (ST or DR). We summarised results in both a risk of bias graph and a risk of bias summary. Results of meta‐analyses were interpreted in light of the findings with respect to risk of bias. We contacted study authors to ask for additional information or for further clarification of study methods if any doubt surrounded potential sources of bias. Individual risk of bias items can be seen in Appendix 7.

Measures of treatment effect

For the purposes of this review, all exercise behaviour was synthesised as specified in the primary outcomes. For comparison of measures of change in fitness levels or estimated energy expenditure from free living physical activity, please see the section on "Continuous data", Data synthesis.

Unit of analysis issues

We included no cross‐over trials in this review because of the high risk of contamination. It can be very difficult to “wash out” exercise behaviour. Cancer survivors in particular can be a highly motivated cohort, and significant contamination has been reported even in conventional RCT settings (Courneya 2003; Mock 2005). Indeed, some trials have reported significant maintenance up to three months after cessation of the intervention.(Bourke 2011). Hence this learning effect distorts results. Furthermore, asking individuals to revert to sedentary behaviour could be considered unethical (Das and Horton 2012). Therefore, any cross‐over trials identified were rejected at the title and abstract screening stage.

Dealing with missing data

We assessed missing data and dropout rates for each of the included studies and reported the numbers of participants included in the final analysis as a proportion of all participants included in the study. We assessed the extent to which studies conformed to an intention‐to‐treat analysis.

Assessment of heterogeneity

Consistency of results was assessed visually and through examination of the I2 statistic, a quantity that describes approximately the proportion of variation in point estimates that is due to heterogeneity rather than sampling error. I2 greater than or equal to 50% was considered significant heterogeneity. We addressed this by performing a sensitivity analysis that excludes any heterogeneous trials. We supplemented this with a test of homogeneity to determine the strength of evidence that the heterogeneity is genuine. When significant statistical heterogeneity was detected, differences in characteristics of the studies or other factors were explored as possible sources of explanation. Any differences were summarised in a narrative synthesis.

Assessment of reporting biases

Publication bias

We intended to examine funnel plots corresponding to meta‐analysis of the primary outcomes to assess the potential for small study effects such as publication bias if a sufficient number of studies (i.e. more than 10) was identified. However, this was not the case; therefore this step was not included in the analysis.

Data synthesis

Continuous data

For continuous outcomes (e.g. cardiorespiratory fitness), we extracted the final value, the standard deviation of the outcome of interest and the number of participants assessed at endpoint for each treatment arm at the end of follow‐up, to estimate standardised mean differences between treatment arms.

Dichotomous outcomes

For dichotomous outcomes (e.g. adverse effects, deaths), if it was not possible to use a hazard ratio, we extracted the number of participants in each treatment arm who experienced the outcome of interest and the number of participants assessed at endpoint, to estimate a risk ratio.

Meta‐analysis

When possible, and if appropriate, we performed a meta‐analysis of review outcomes. If statistical heterogeneity was noted, a meta‐analysis was performed using a random‐effects model. A fixed‐effect model was to be used if no significant statistical heterogeneity was observed.

When possible, all data extracted were those relevant to an intention‐to‐treat analysis in which participants were analysed in groups to which they were assigned. We noted the time points at which outcomes were collected and reported.

Subgroup analysis and investigation of heterogeneity

If a sufficient number of studies were identified, we performed subgroup analyses for the following.

  • Cancer site.

  • Type of intervention (i.e. supervised, home‐based, etc).

  • Age of individuals (i.e. elderly vs non‐elderly).

  • Current treatment (currently undergoing treatment vs not currently undergoing treatment).

  • Participants with metastatic disease (metastatic cohort vs non‐metastatic cohort).

  • Accordance with behaviour change theory.

  • Interventions in obese individuals (mean body mass index (BMI) of intervention group > 30 kg/m2 vs mean BMI of intervention group < 30 kg/m2).

Sensitivity analysis

Methodological flaws were judged using the Cochrane Collaboration's tool for assessing risk of bias to identify studies of high and low quality (Higgins 2011). Sensitivity analyses were performed with the studies of low quality excluded.

Results

Description of studies

Please see Table 1, 'Summary of included studies'. See 'Characteristics of included studies'; 'Characteristics of excluded studies'; 'Characteristics of studies awaiting classification'; and 'Characteristics of ongoing studies'.

Open in table viewer
Table 1. Summary of included studies

Study

Exercise components

n

Meets Rock et al guidelines?

Adherence summary

At least 75% adherence?

High risk of bias?

Change in AET reported?

Adverse effects

Cadmus 2009

Aerobic

37, 38 (intervention vs control)

33% reported 150 minutes/wk of moderate intensity aerobic exercise at an average of 76% HR, for six months

75% of women were doing between 90 and 119 minutes of moderate intensity aerobic activity per week at six months

Yes; for up to 119 minutes per week

No

No

Five of the 37 women randomly assigned to exercise experienced an adverse effect; two were related to the study (plantar fasciitis)

Daley 2007a

Aerobic

34, 36, 38 (intervention,

sham, control, respectively)

No

77% of the exercise therapy; attended 70% (at least 17 of 24 sessions) or more of sessions

Unclear

Yes; outcome assessors were not blinded to participants’ group allocation

Yes

Three withdrawals in the intervention group: unclear as to why this occurred. Some withdrawals because of medical complications in placebo and control arms but unclear whether study related

Drouin 2005

Aerobic

13 intervention, 8 placebo stretching controls

Unclear

Participants in the intervention group averaged 3.6 days per week of aerobic exercise over an 8‐week period

Unclear

No

Yes

None reported

Kaltsatou 2011

Aerobic

14, 13 (intervention vs control)

Unclear

Not reported

Not reported

Yes; method of measuring exercise and adherence not reported

No

None reported

Kim 2006

Aerobic

22,19 (intervention vs control).

No

Average weekly frequency of exercise was 2.4 ± 0.6 sessions, and average duration of exercise within prescribed target HR was 27.8 ± 8.1 minutes per session. Overall adherence was 78.3% ± 20.1%

Yes

Yes; data missing for 45% of the cohort

Yes

Reasons for withdrawal included personal problems (n = 2), problems at home (n = 2), problems related to chemotherapy (n = 3), thrombophlebitis in the lower leg (n = 2), non-exercise‐related injuries (n = 1), and death (n = 1). Unclear to which arm of the trial these date relate

Pinto 2003

Aerobic

12, 12 (intervention vs

control)

Unclear

Participants attended a mean of 88% of the 36‐session supervised exercise programme

Yes

Yes; 38% lost to follow‐up. Exercise tolerance test was performed but no control group comparison data were reported

Yes

None reported; however, it is unclear why the six controls dropped out

Pinto 2005

Aerobic

43, 43 (intervention vs control)

Unclear

At week 12, intervention participants reported a mean of 128.53 minutes/wk of moderate intensity exercise. However, no changes were reported in the accelerometer data in the intervention group (change score = ‐0.33 kcal/h)

Less than 75% of the intervention group was meeting the prescribed goal after week 4

Yes; significantly more control group participants were receiving hormone treatment. Accelerometer data do not support the self‐reported physical activity behaviour

Yes

Not clear whether chest pain was related to exercise in dropout whose participation was terminated

Pinto 2011

Aerobic

20, 26 (intervention vs control)

Three‐day PAR questionnaire indicates that 64.7% of the intervention group and 40.9% of the control group were achieving the guidelines at three months

Correlation between self‐reported moderate intensity exercise and accelerometer data at three‐month follow‐up, when the only significant between‐group change is reported: r = 0.32

No

Yes; accelerometer data were not reported; also, cited correlation is weak (0.32). Further, substantial contamination was noted in the control group

Yes

One cancer recurrence in the control group at three months

Bourke 2011a

Aerobic and resistance

9, 9 (intervention vs control)

Six weeks of resistance exercise twice a week

90% attendance at the supervised sessions. 94% of independent exercise sessions were completed

Yes

No

Yes

One stroke in the intervention group, unrelated to the exercise programme

Bourke 2011b

Aerobic and resistance

25, 25 (intervention vs control)

Six weeks of resistance exercise twice a week

95% attendance at supervised exercise sessions. Compliance with self‐directed exercise aspect of the lifestyle intervention was 87%

Yes

Yes; high dropout rate at postintervention six‐month follow‐up assessment

Yes

Two men in the intervention arm were discontinued because of cardiac complications before the 12‐week assessments. Two more reported musculoskeletal complaints before the six‐month assessment. Five men reported various health problems in the control group that prohibited them from attending the six‐month assessment

Hayes 2009

Aerobic and resistance

16, 16 (intervention vs control)

Unclear

Most women (88%) allocated to the intervention group participated in 70% or more of scheduled supervised exercise sessions

Unclear

Yes; adherence data on unsupervised aspect of the intervention are not clear

No

None reported

McKenzie 2003

Aerobic and resistance

7,7 (intervention vs control)

No

Unclear

Unclear

Yes; adherence to exercise not reported

No

None reported

Musanti 2012

Aerobic and resistance

Flexibility group (n = 13), aerobic group (n = 12), resistance group (n = 17), aerobic and resistance group (n = 13)

12 weeks of resistance exercise two or three times per week

Mean percentages of adherence were as follows: flexibility = 85%, aerobic = 81%, resistance = 91% and aerobic plus resistance = 86%

Unclear

Yes; a significant number of dropouts belonged to the resistance exercise group (n = 8/13). Only 50% of activity logs were returned

Yes

Adverse effects were reported in two women during the study. In both cases, the women developed tendonitis: one in the shoulder and the other in the foot. Both had a history of tendonitis, and both received standard treatment

Perna 2010

Aerobic and resistance

51 participants in total. Numbers randomly assigned to each arm are unclear

Three months of resistance exercise three times per week

Women assigned to the structured intervention completed an average of 83% of their scheduled hospital‐based exercise sessions (only 4 weeks in duration), and 76.9% completed all 12 sessions. Home‐based component (8 weeks in duration)

Unclear

Yes; numbers randomly assigned to intervention and control groups are unclear, as are numbers completing in each arm

No

Unclear

AET = aerobic exercise tolerance.

Results of the search

Figure 1 illustrates the process of the literature search and study selection for the review. We identified 4827 unique records from research databases and 732 records through grey literature and "snowballing" techniques, which included reference checking from recent large systematic reviews (Fong 2012; Mishra 2012a; Mishra 2012b). Given that the details of prescribed exercise are rarely reported in manuscript abstracts (e.g. frequency, intensity, duration of exercise prescription), this led to evaluation of a large number of manuscripts at full text stage (n = 402). From these full text articles, 377 manuscripts were excluded, leaving 25 publications included in the review. Reasons for excluding these 377 publications are covered in the Excluded studies section below.


PRISMA flow diagram.

PRISMA flow diagram.

Included studies

After consensus agreement was reached by review authors (LB and KH), 14 trials were included in this review (Bourke 2011a; Bourke 2011b; Cadmus 2009; Daley 2007a; Drouin 2005; Hayes 2009; Kaltsatou 2011; Kim 2006; McKenzie 2003; Musanti 2012; Perna 2010; Pinto 2003; Pinto 2005; Pinto 2011). We also included in our analysis 11 follow‐up papers that performed secondary analyses of data from a primary RCT. We sent 116 emails to request unpublished information for manuscripts that were unclear in reporting relative to our inclusion/exclusion criteria. We were able to include 15 and to exclude 34 published manuscripts on the basis of information received in correspondence from authors.

Only RCTs were included in the review. All included trials used a parallel‐group design with baseline assessment and follow‐up of 12 months maximum. All included trials were conducted using participant level randomisation. The format of reporting precluded data extraction for meta‐analytical combination in two studies (Drouin 2005; Pinto 2003). Sample size ranged from 14 to 108, with a total of 648 participants included in this review (mean age range 51 to 72).

Participants

Most trials were conducted in breast cancer survivors (Cadmus 2009; Daley 2007a; Drouin 2005; Hayes 2009; Kaltsatou 2011; Kim 2006; McKenzie 2003; Musanti 2012; Perna 2010; Pinto 2005; Pinto 2003); only two trials involved colorectal cancer (Bourke 2011a; Pinto 2011), and one prostate cancer (Bourke 2011b). Of these trials, eight included participants who were currently undergoing active treatment inclusive of hormone‐based therapy (Bourke 2011b; Cadmus 2009; Daley 2007a; Drouin 2005; Kim 2006; Musanti 2012; Perna 2010; Pinto 2005). We found only one study that reported data from participants with metastatic disease (Bourke 2011b) and two that were conducted in obese cohorts (i.e. mean BMI > 30 kg/m2; Cadmus 2009; Drouin 2005). An overwhelming proportion of participants were white, and only one study reported data from an ethnically diverse sample (Perna 2010). Comorbidities at baseline were largely unclear or unreported; only Daley 2007a and Hayes 2009 reported on proportions with lymphedema, and Perna 2010 reported on proportions with clinically relevant depression scores.

Interventions

Eight trials prescribed exclusively aerobic exercise (Cadmus 2009; Daley 2007a; Drouin 2005; Kaltsatou 2011; Kim 2006; Pinto 2003; Pinto 2005; Pinto 2011); the remaining RCTs used a mix of aerobic and resistance training (no exclusively resistance training studies met our inclusion criteria). Seven trials used a combination of supervised and home‐based exercise (Bourke 2011a; Bourke 2011b; Cadmus 2009; Hayes 2009; Kim 2006; Perna 2010; Pinto 2003), four trials opted to use an exclusively home‐based design (Drouin 2005; Musanti 2012; Pinto 2005; Pinto 2011), and only three were exclusively supervised trials (Daley 2007a; Kaltsatou 2011; McKenzie 2003). Contact with exercise professionals or study researchers ranged from 20 times over 12 weeks (Hayes 2009) to weekly phone calls after an initial one‐to‐one exercise consultation (Pinto 2005; Pinto 2011). Of note, seven trials (Drouin 2005; Kaltsatou 2011; Kim 2006; McKenzie 2003; Pinto 2003; Pinto 2005; Pinto 2011) placed restrictions on the control group regarding exercise behaviour during the course of the trial, usually taking the form of direct instruction to refrain from changing exercise behaviour. Just six trials incorporated prescriptions that would meet the Rock 2012 recommendations for aerobic exercise (i.e.150 minutes per week; Cadmus 2009; Pinto 2011) or resistance exercise (i.e. resistance training strength training exercises at least two days per week; Bourke 2011a; Bourke 2011b; Musanti 2012; Perna 2010). Only three trials were identified that attempted to objectively validate independent exercise behaviour with accelerometers or heart rate monitoring (Cadmus 2009; Pinto 2005; Pinto 2011).

Full details of intervention (behaviour change technique (BCT)) coding according to the CALO‐RE taxonomy can be seen in Table 2. Of the 14 interventions provided, only five were explicitly based on a theoretical model (Daley 2007a; Musanti 2012; Perna 2010; Pinto 2005; Pinto 2011); the trans‐theoretical model was most common. All interventions had a target exercise level set by the programme. Only sjx trials set exercise goals in conjunction with participants (BCT # 5). In addition, all prompted practise of the behaviour (BCT #26), and all but four (Bourke 2011a; Hayes 2009; McKenzie 2003; Pinto 2005) reported providing instruction on how to perform the behaviour (BCT #21), although it may be anticipated that this did occur but just was not reported. Other common BCTs included setting of graded tasks (i.e. increased exercise duration or intensity over time) and self‐monitoring of behaviour (exercise) and outcomes of behaviour (e.g. heart rate), although it is not clear for all interventions whether this was done primarily for data collection or as a mechanism of behaviour change. It is important to note that when monitoring did occur (BCT #16), feedback on performance (BCT #19) was provided in only 4/10 (Cadmus 2009; Perna 2010; Pinto 2005; Pinto 2011). Similarly, in only two of six interventions (Daley 2007a; Perna 2010) for which participants had some input into setting of goals were these reviewed (BCT #10). Of note, few interventions (Cadmus 2009; Daley 2007a; Kim 2006; Perna 2010) reported providing information on the consequences of behaviour (BCT #1), although less than half reported problem solving with barriers identified (BCT #8) and solutions facilitated (Bourke 2011b; Cadmus 2009; Daley 2007a; Perna 2010; Pinto 2005; Pinto 2011). Only three trials used techniques to increase social support (BCT #29; Cadmus 2009; Daley 2007a; Perna 2010).

Open in table viewer
Table 2. Behaviour change components

Behaviour change technique

Bourke 2011a

Bourke 2011b

Cadmus 2009

YALE

Daley 2007a

Drouin 2005

Hayes 2009

Kaltsatou 2011

McKenzie 2003

Musanti 2012

Perna 2010

Kim 2006

Pinto 2003

Pinto 2005

Pinto 2011

Theory

TTM

EXSEM

TTM

TTM

TTM SCT

1. Provide Info on consequences of behaviour in general

X

X

X

X

2. Provide Info on consequences of behaviour to the individual

3. Provide Info about others' approval

4. Provide normative info about others' behaviour

Programme set goal

X

X

X

X

X

X

X

X

X

X

X

X

X

X

5. Goal setting (behaviour)

X

X

X

X

X

X

6. Goal setting (outcome)

7. Action planning

8. Barrier identification/Problem solving

X

X

X

X

X

X

9. Setting of graded tasks

X

X

X

X

X

X

X

X

X

10. Prompt review of behavioural goals

X

X

11. Prompt review of outcome goals

12. Prompt rewards contingent on effort or progress towards goal

X

X

X

13. Provide rewards contingent on successful behaviour

X

14. Shaping

15. Prompt generalisation of a target behaviour

X

X

X

X

X

16. Prompt self‐monitoring of behaviour

X

X

X

X

X

X

X

X

X

X

17. Prompt self‐monitoring of behavioural outcome

X

X

X

X

X

X

18. Prompt focus on past success

X

19. Feedback on performance provided

X

X

X

X

20. Information provided on where and when to perform behaviour

X

X

21. Instruction provided on how to perform the behaviour

X

X

X

X

X

X

X

X

X

X

22. Modelling/Demonstration of behaviour

X

X

X

23. Teaching to use prompts/cues

X

X

X

24. Environmental restructuring

X

X

25. Agreement on behavioural contract

X

26. Prompt practise

X

X

X

X

X

X

X

X

X

X

X

X

X

X

27. Use of follow‐up prompts

X

X

28. Facilitating social comparison

29. Planning social support/social change

X

X

X

30. Prompt identification as role model/position advocate

31. Prompt anticipated regret

32. Fear arousal

33. Prompt self‐talk

34. Prompt use of imagery

35. Relapse prevention/coping planning

X

X

36. Stress management/emotional control training

X

37. Motivational interviewing

38. Time management

39. General communication skills training

40. Stimulation of anticipation of future rewards

EXSEM = exercise self‐esteem model; SCT = social cognitive theory; TTM = transtheroretical model.

Excluded studies

Reasons for excluding published studies included the following.

  • Non‐RCTs (e.g. review manuscripts, comment/editorial articles).

  • Mixed cancer cohorts or cohorts that included non‐cancer populations.

  • Trials that failed to describe essential metrics of exercise prescription used in the intervention (e.g. frequency, intensity, duration).

  • Trials involving active participants at baseline.

  • Trials involving hospital inpatients.

  • Interventions that provided follow‐up of less than 6 weeks.

  • Trials involving participants younger than 18 years of age.

Because of the volume of studies identified by the search, only the first occurrence of an exclusion criterion was noted in the publication, although frequently, trials exhibited several of the criteria listed above. Therefore, it was neither valid nor informative to present the number of papers excluded under each of the reasons listed above. The extent of exclusion at the full text screening stage (377 publications excluded from 402) provided the first indication of problems associated with quality of reporting in this research area. We sent emails to 116 corresponding authors to request additional information (regarding included studies, excluded studies and studies that we could not access) to determine eligibility and to supplement published data for this review.

Only a subset of excluded studies could be included in the 'Characteristics of excluded studies' section. This is a result of the huge volume of trials that had to be full text screened (N = 402) and the high proportion (around 90%) that were excluded. In accordance with editorial advice, we divided this large number (N = 365) into initially unclear trials that required further investigation (N = 76) and those that clearly were not eligible after full text had been retrieved (N = 289). This approach is analogous to the approach adopted in recent reviews (Galway 2012) and is detailed in the existing PRISMA diagram (Figure 1).

Risk of bias in included studies

Only three trials were judged not to include a high risk of bias (Bourke 2011a; Cadmus 2009; Drouin 2005). Full results of the methodological quality assessment for allocation bias, blinding, incomplete data outcome and selective reporting (along with justifications) are covered in the risk of bias tables for each study and are illustrated in Figure 2 and Figure 3. Seven trials stated that an intention‐to‐treat analysis was used (Bourke 2011a; Bourke 2011b; Cadmus 2009; Daley 2007a; Perna 2010; Pinto 2005; Pinto 2011).


Risk of bias summary: review authors' judgements about each risk of bias item for each included study.

Risk of bias summary: review authors' judgements about each risk of bias item for each included study.


Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

Allocation

Most trials (8 out of 14) were not clear in their description of concealment in randomisation allocation. However, no trial was judged to have a high risk of bias in this respect.

Blinding

Only four trials explicitly stated whether they had undertaken blinding of study assessors (Bourke 2011a; Bourke 2011b; Daley 2007a; Hayes 2009). The remaining trials did not include enough information for the review authors to make a definitive judgement on this criterion.

Incomplete outcome data

Four trials were judged to have been subject to incomplete data outcome bias. Bourke 2011b reported a 44% attrition at six months of follow‐up; Kim 2006 reported data from only 41 of 74 participants randomly assigned; Musanti 2012 reported that 13 women (24%) did not complete their assigned 12‐week programme; and Pinto 2003 did not report control group data for the exercise tolerance test. However, most studies (8 out of 14) were explicit in their reporting of outcomes.

Selective reporting

Most studies reported all listed outcomes; however, three trials were judged to omit outcomes from their results reporting. Musanti 2012 did not report waist and upper, mid and lower arm circumference outcomes; Pinto 2003 reported none of the physiological assessments in the control group at 12 weeks of follow‐up; Pinto 2011 did not report data derived from the use of accelerometers.

Other potential sources of bias

Other sources of bias found in the included trials that are worth highlighting include adherence data missing or not clear (Hayes 2009; Kaltsatou 2011; McKenzie 2003; Musanti 2012); high attrition at follow‐up (Bourke 2011b; Pinto 2003); low recruitment rate (Bourke 2011a); significant differences in participants excluded from trial analysis/dropouts (Kim 2006; Musanti 2012; Pinto 2003); numbers randomly assigned to trial arms with trial completion rate unclear (Perna 2010); significant differences in cohorts at baseline (Musanti 2012; Pinto 2003; Pinto 2005); and inconsistencies between objective and subjective measures of exercise behaviour (Pinto 2005; Pinto 2011). Insufficient information was reported to permit a judgement about any single element of bias because of lack of data in Cadmus 2009; Drouin 2005; Hayes 2009; Kaltsatou 2011; Kim 2006; McKenzie 2003; Pinto 2003; Pinto 2005; and Pinto 2011.

Effects of interventions

Primary outcomes

Please see Table 1, 'Summary of included studies'. As it is not meaningful to interpret individually the component metrics of aerobic (frequency, intensity and duration) or resistance exercise (frequency, intensity, type of exercise, sets and repetitions) behaviour, these primary outcomes are presented in the narrative synthesis below of interventions achieving 75% or greater adherence.

None of the trials included in this review reported that 75% or more of the intervention group met the Rock 2012 aerobic exercise guidelines at any given follow‐up. Only three trials reported adherence of 75% or greater to their specified aerobic exercise prescription (Bourke 2011a; Bourke 2011b; Cadmus 2009). It is notable that all three incorporated both a supervised and an independent exercise component as part of their intervention, and none placed restrictions on the control group in terms of exercise behaviour. Cadmus 2009 was likely the most successful study regarding the promotion of aerobic exercise behaviour, with 75% of the intervention group reporting between 90 and 119 minutes per week of moderate intensity exercise, at an average heart rate of 76% of predicted maximum, for six months. However, of these three trials, only Bourke 2011a and Bourke 2011b met the Rock 2012 exercise guidelines. Specifically, two to four sets of resistance exercise at 60% of one repetition max (RM) for eight to 12 repetitions were carried out twice per week for just six weeks. These three trials all shared the following BCTs.

  • Programming a set goal.

  • Prompting generalisation of a target behaviour.

  • Prompting self‐monitoring of behaviour.

  • Prompting practise.

Aside from generalisation of a target behaviour, these three interventions did not differ from other interventions in terms of BCTs reported. Nor did trials explicitly state a theoretical basis. Other studies such as Daley 2007a and Perna 2010 were much more comprehensive in their reporting of BCTs and were based on recognised behaviour change theory. Several trials might have achieved adherence of 75% or greater, but because of unclear reporting, it was not possible to make a judgement on whether this criterion had been fulfilled. Reasons for judgement of unclear or unsuccessful adherence are detailed below.

  • Daley 2007a: judgement unclear; adherence reported as a proportion of participants attending a proportion of set exercise sessions (i.e. 77% of the intervention group attending 70% of sessions).

  • Drouin 2005: judgement unclear; adherence reported as mean number of days per week when exercise was undertaken, relative to a range within the prescription (i.e. 3.6 days per week, when the prescription was for three to five days per week).

  • Kaltsatou 2011: judgement unclear; no adherence data reported.

  • Kim 2006: judgement unclear; high adherence was reported (78%) but in tandem with substantial attrition (i.e. data missing for 45% of the cohort).

  • Pinto 2003: judgement unclear; high adherence was reported (88%) but in tandem with substantial attrition (i.e. 25% of the intervention group dropped out over the intervention period).

  • Pinto 2005: judgement unsuccessful; 75% adherence threshold was not met after week 4.

  • Pinto 2011: judgement unsuccessful; three‐day PAR questionnaire indicates that 64.7% of the intervention group and 40.9% of controls were adhering to the exercise guidelines at three months.

  • Hayes 2009: judgement unclear; adherence reported as a proportion of participants attending a proportion of set exercise sessions (i.e. 88% allocated to the intervention group participated in 70% or more of scheduled supervised exercise sessions). Further, adherence from the unsupervised aspect is not reported.

  • McKenzie 2003: judgement unclear; no adherence data reported.

  • Musanti 2012: judgement unclear; high adherence reported but only 50% of activity logs returned.

  • Perna 2010: judgment unclear; women assigned to the structured intervention completed an average of 83% of their scheduled hospital‐based exercise sessions (4 weeks in total). Home‐based adherence is not clear.

Ideally, a meta‐analysis of objectively verified (e.g. using accelerometers or heart rate monitoring) minutes per week of moderate intensity aerobic exercise achieved in an intervention group, compared with controls, for whom the exercise prescription adherence is at least 75%, would be most informative. Among trials with at least 75% adherence, only Cadmus 2009 reported behaviour in these terms. However, this trial demonstrated adherence rates of 75% or more only for 90 to 119 minutes per week of moderate intensity exercise. The overall mean (standard deviation (SD)) reported for minutes of moderate intensity physical activity at six months of follow‐up was 161.7 (114.7) minutes, as reported by the 7‐Day Physical Activity Log, with adherence reported as 61%. The other two trials (Bourke 2011a; Bourke 2011b) reported overall exercise behaviour using Godin Leisure Index questionnaire (Godin 1986) scores (without full objective validation). Further, at the same follow‐up point of six months, Bourke 2011b reported 44% attrition and hence was judged as having a high risk of bias. Bourke 2011a reported outcomes at just 12 weeks of follow‐up. Hence, a meta‐analysis of moderate intensity exercise behaviour at any given follow‐up was judged to be not informative. Insuficent data were available for a synthesis of evidence to be conducted around free living energy expenditure. Planned subgroup analysis was not deemed informative because of the lack of identified studies.

Secondary outcomes

A meta‐analysis of change in aerobic exercise tolerance was carried out on seven trials that reported these outcomes and also reported means for final value scores. Standardised mean differences (SMDs) were used to produce effect estimates as variation in how trials assessed this outcome was evident. Standard deviations (SDs) were calculated from 95% confidence intervals (CIs) using the formula in the Cochrane Handbook for Systematic Reviews of Interventions (i.e. SD = √N * (upper limit‐lower limit)/(t distribution *2), and from standard errors (SEs) using SD = SE*√N, when they were not reported. Length of follow‐up ranged from eight (Kim 2006; Daley 2007a) to 12 weeks (Bourke 2011a; Bourke 2011b; Musanti 2012; Pinto 2005; Pinto 2011; see Analysis 1.1). Aerobic exercise tolerance was significantly better in intervention versus control groups in 330 participants: SMD 0.73, 95% CI 0.51 to 0.95). We then removed trials with a high risk of bias relative to this outcome and repeated the analysis with the three remaining trials (Bourke 2011a; Bourke 2011b; Pinto 2005; see Analysis 1.2); aerobic exercise tolerance was significantly better in intervention versus control groups in 154 participants: SMD 0.84, 95% CI 0.51 to 1.17). We were unable to analyse subgroups outlined in the protocol (i.e. by cancer site, type of intervention, etc) because of a lack of included studies reporting changes in aerobic exercise tolerance or fitness. Five trials included data from a follow‐up of six months (Bourke 2011b; Daley 2007a; Kaltsatou 2011; Pinto 2005; Pinto 2011) showing that aerobic exercise tolerance was significantly better at six months in intervention versus control groups in 271 participants: SMD 0.70, 95% CI 0.45 to 0.94; see Analysis 1.3). However, it should be highlighted that four of these trials have a high risk of bias, which could affect this outcome at six months, specifically, a high risk of reporting bias at six months in the Bourke 2011b trial; no adherence data in the Kaltsatou 2011 trial; substantial contamination among controls in the Pinto 2011 trial; and non‐blinded assessors in the Daley 2007a trial. Note that in all meta‐analyses, data from Pinto 2005 have been multiplied by ‐1 to control for direction of effect (i.e. lower values in a timed test indicate a better outcome). Data were extracted from the combined aerobic and resistance training arm of Musanti 2012.

Brief narrative descriptions of studies not suitable for meta‐analyses include the following: Drouin 2005 VO2 peak data are reported as medians and interquartile ranges; for Pinto 2003, no control group data are presented for the exercise tests.

Three trials that used resistance exercise as a component of the intervention reported changes in lower (Bourke 2011a; Bourke 2011b) and upper limb (Musanti 2012) strength. All three trials had reported strength changes at 12 weeks of follow‐up, and we were able to extract means and SDs. Limb strength was significantly better in intervention versus control groups for 91 participants: SMD 0.51, 95% CI 0.19 to 0.93; see Analysis 2.1). After one trial was removed for high risk of bias (Musanti 2012), the moderate effect size was still apparent in 68 participants, but it was no longer significant: SMD 0.47, 95% CI ‐0.01 to 0.96; see Analysis 2.2).

Just six trials produced CONSORT diagrams (Bourke 2011a; Bourke 2011b; Cadmus 2009; Daley 2007a; Pinto 2005; Pinto 2011). Intervention attrition rates from the included trials ranged from 25% (Pinto 2003) to 0% (Drouin 2005) (median 6%), with five trials not clearly reporting attrition in the intervention arm (Kaltsatou 2011; Kim 2006; McKenzie 2003; Musanti 2012; Perna 2010). Eight trials reported adverse effects (Bourke 2011a; Bourke 2011b; Cadmus 2009; Daley 2007a; Kim 2006; Musanti 2012; Pinto 2005; Pinto 2011); these ranged from minor (e.g. musculoskeletal problems; Musanti 2012) to major events (e.g. death; Kim 2006). However, only one study (Cadmus 2009) was explicit as to which of these adverse effects were caused by inclusion of the participant in the intervention group (two instances of plantar fasciitis). The trial recruitment rate ranged from 10% (Bourke 2011a) to 89% (Perna 2010). Eight trials reported a priori sample size estimates (Cadmus 2009; Daley 2007a; Hayes 2009; Kaltsatou 2011; Musanti 2012; Pinto 2003; Pinto 2011; Perna 2010), and only three (Cadmus 2009; Hayes 2009; Perna 2010) met their recruitment target.

Discussion

Summary of main results

Review findings indicate that currently, convincing evidence are lacking to suggest that existing exercise interventions are useful for achieving the Rock 2012 guidelines of 150 minutes per week of aerobic exercise and twice per week of resistance exercise in sedentary cancer cohorts. Adherence to exercise interventions, which is crucial for understanding treatment dose, is frequently poorly reported. It is important to note that the fundamental metrics of exercise behaviour (i.e. frequency, intensity and duration, or repetitions, sets and intensity of resistance training), although easy to devise and report, are seldom included in published clinical trials. Attempts to reproduce any exercise prescription without detailing these metrics are fraught with problems; most likely, this is not possible. The supportive evidence that we have synthesised as a narrative suggests that interventions that combine supervision of exercise training in tandem with a requirement for independent exercise are likely to promote better adherence. Behaviour change techniques (BCTs) that include programming set goals, prompting self‐monitoring and practicing and generalising behaviour are a common feature of interventions that have reported better adherence.

Despite the uncertainty surrounding adherence in many of the included trials, interventions caused improvement in aerobic exercise tolerance at 8 to 12 weeks: SMD 0.73, 95% CI 0.51 to 0.95) in intervention participants compared with controls. At six months, aerobic exercise tolerance was also improved: SMD 0.70, 95% CI 0.45 to 0.94), but it should be noted that four of the five trials used in this analysis had a high risk of bias, hence caution is warranted in interpretation of findings. Such improvements could be interpreted as reassuring that some of the lack of clarity around adherence extends only to reporting issues rather than reflecting real problems with fidelity. Alternatively, this result could have arisen from the rapid, relatively large early gains in function expected in sedentary participants as the result of exercise training, which could mask smaller changes among non‐adherers. Further, aerobic exercise tolerance should not be considered as definitive evidence of changes in aerobic fitness (with the accompanying spectrum of underlying physiological adaptations). It could simply reflect the fact that individuals have become accustomed to the feeling of exertion from exercise testing and better tolerance towards perceptions of fatigue. Just one of the included trials (Drouin 2005) reported using established cardiopulmonary exercise testing protocols to measure changes in fitness (e.g. VO2 peak derived from Douglas bag or online gas analysis systems). However, this study did not report data that we could use in our meta‐analysis (i.e. only medians and ranges were reported). It is interesting to note that reported attrition over the intervention period for trials included in this review was typically low (median 6%), although it is difficult to interpret adverse effect reports and to identify adverse effects that are attributable to participation in these interventions.

Overall completeness and applicability of evidence

This systematic review included 14 trials, all of which were RCTs. These trials randomly assigned 648 participants to exercise or comparison groups. A large majority of these trials included women with breast cancer. One trial involved men with advanced prostate cancer, and two trials involved colorectal cancer survivors. Although these three primary cancers account for most of the population living with and beyond cancer, other common cancers such as lymphoma and lung cancer do not appear at all in this review. Less common cancers also are not represented in the evidence base. Furthermore, an overwhelming majority of participants were white, and only one trial included an ethnically diverse population. As such, other ethnicities are substantially underrepresented. Although we set a limit in this review of 90 minutes per week of moderate intensity exercise at baseline as the criterion for categorising participants as "sedentary", we did not specify any threshold for vigorous exercisers. It is possible that we could have included individuals who were performing as much as 90 minutes per week of vigorous intensity exercise. Such individuals would be erroneously designated as "sedentary". However, given the population under study, it is likely that such contamination would be minimal. We set a threshold of 75% adherence for any trial to be judged "successful" in this review. This decision was based on previous reports from a review of adherence to exercise schemes in older adults (Martin 2001). This threshold of course is open to debate in the context of cancer specifically, but it was believed that this level represents a minimum for achieving balance between a meaningful dose of the stated exercise prescription and what is realistic for most people living with and beyond cancer. Thirteen of the 14 included trials were conducted in Northern America or Western Europe, and one trial was completed in Australia. All are considered high income nations according to the World Health Organization (WHO) taxonomy. No evidence was derived from developing countries, and it is uncertain whether the resources and/or infrastructure required for some of the interventions included in this review would be applicable in these parts of the world.

Although no single tool for measuring physical activity is infallible (Warren 2010), when possible it is desirable to have self‐reported exercise behaviour supported by objective measurements such as accelerometers or heart rate data. An overwhelming majority of trials evaluated non‐supervised exercise behaviour by using self‐report logs or seven‐day physical activity questionnaires. Whilst these tools are relatively non‐complex and affordable for implementation in trial design, they are prone to multifarious bias, including difficulties in ascertaining the frequency, duration and intensity of physical activity; social desirability bias; the cognitive demands of recall and overestimation of behaviour, particularly when such data are used to extrapolate MET/hours of exercise per week performed, or kcal/wk of energy expenditure. It is admirable that two trials attempted to validate self‐reported independent exercise behaviour by using accelerometers (Pinto 2005; Pinto 2011); however, data either were not supportive of exercise behaviour recorded by participants or were not reported in their entirety.

Analysis by behaviour change theory and outcome (e.g. aerobic exercise tolerance) was not possible given that few trials stated a theoretical basis for their intervention. It is worthy of note, however, that interventions frequently consisted of little more than telling people how to exercise and providing opportunities for this to occur, with little consideration of the psychological aspects of changing behaviour. It is also acknowledged that although coding of BCTs was done primarily on the basis of study reports, it is possible that some BCTs may have been implemented but not reported. To overcome this possibility and enhance understanding of the techniques important for changing behaviour in cancer patients, adoption of the CALO‐RE taxonomy or the broader BCT v1 taxonomy is recommended.

We acknowledge that in this review, we have undertaken a synthesis of RCTs that represent a combination of exercise efficacy and behaviour change trials (Courneya 2010), and we recognise the distinction. However, it should be noted by the reader that all three trials that we judged as successful (i.e. reported 75% or greater adherence over the intervention period) incorporated intervention elements that were designed to promote independent exercise behaviour and did not place any restrictions on the control group in terms of the exercise they were permitted to undertake during the trial. Finally, we stated in the justification for this review that a better understanding of the types of interventions that could promote long‐term, habitual physical activity (i.e. 12 months or longer) in people living with and beyond cancer was a valuable addition to our knowledge. Unfortunately, because of limitations in the evidence that we identified, we have not been able to address this issue. As such, this is an area of uncertainty that represents an important research gap.

Quality of the evidence

Most of the uncertainty in judging trial bias came from lack of clarity around randomisation procedures and blinding of study outcome assessors. Most of the trials in this review were judged to include at least one element of high risk of non‐standard bias, as described in the 'Other sources of bias' outcome. Of note, we chose to refrain from judging trials according to the performance bias criterion because we considered it not possible to realistically blind intervention participants to "sham" conditions. Public health guidelines (e.g. the UK CMO report) for aerobic and resistance exercise (which are identical to the Rock et al recommendations) are freely available to the public, and given their ease of access via the Internet, the validity of a "sham" condition is dubious. The 'Summary of findings' and 'Risk of bias' tables and Figure 2 and Figure 3 provide a summary of the quality of evidence.

Potential biases in the review process

We were not able to translate all non‐English language studies identified through our database, grey literature and snowballing searches. However, a huge effort was made to identify all relevant RCTs in this field. To the review authors' knowledge, we have identified and evaluated more RCTs involving exercise interventions in people living with or beyond cancer than any other systematic review in this field. More than 400 papers were screened at full text stage for eligibility, and we sent 116 emails to request data to inform the screening and data extraction process, so that the conclusions of the review would be as accurate and informative as possible. We were able to perform single extraction only to generate the CALO‐RE taxonomy data (undertaken by LS).

Agreements and disagreements with other studies or reviews

To the review authors' knowledge, this is the first comprehensive review to evaluate RCTs with respect to their success in promoting exercise behaviour in sedentary cancer cohorts. A recent systematic review of predictors of adherence to exercise in people living with and beyond cancer (Husebø 2013) found that the trans‐theoretical model of behaviour change and the theory of planned behaviour were significantly associated with better exercise adherence. The current review does not explicitly support such conclusions. It should be noted that key differences are evident in each review methodology, with the present review including only RCTs and people who were sedentary at baseline. Other recent high‐profile systematic reviews (e.g. Fong 2012) have focused on potential health‐related outcomes of exercise intervention for people living with and beyond cancer. In this respect, Fong 2012 similarly reported improvements in aerobic exercise tolerance and muscle strength. One substantial difference in the methodology of the present review when compared with other Cochrane reviews in this area (e.g. Mishra 2012a; Mishra 2012b) is that we included only studies in which the essential metrics of exercise behaviour are reported.

PRISMA flow diagram.
Figures and Tables -
Figure 1

PRISMA flow diagram.

Risk of bias summary: review authors' judgements about each risk of bias item for each included study.
Figures and Tables -
Figure 2

Risk of bias summary: review authors' judgements about each risk of bias item for each included study.

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.
Figures and Tables -
Figure 3

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

Comparison 1 Aerobic exercise tolerance, Outcome 1 Aerobic exercise tolerance (all cancers: 8 to 12 weeks of follow‐up).
Figures and Tables -
Analysis 1.1

Comparison 1 Aerobic exercise tolerance, Outcome 1 Aerobic exercise tolerance (all cancers: 8 to 12 weeks of follow‐up).

Comparison 1 Aerobic exercise tolerance, Outcome 2 Aerobic exercise tolerance (all cancers: 8 to 12 weeks of follow‐up sensitivity analysis).
Figures and Tables -
Analysis 1.2

Comparison 1 Aerobic exercise tolerance, Outcome 2 Aerobic exercise tolerance (all cancers: 8 to 12 weeks of follow‐up sensitivity analysis).

Comparison 1 Aerobic exercise tolerance, Outcome 3 Aerobic exercise tolerance (all cancers: 6 months).
Figures and Tables -
Analysis 1.3

Comparison 1 Aerobic exercise tolerance, Outcome 3 Aerobic exercise tolerance (all cancers: 6 months).

Comparison 2 Strength tests (all cancers), Outcome 1 Strength tests.
Figures and Tables -
Analysis 2.1

Comparison 2 Strength tests (all cancers), Outcome 1 Strength tests.

Comparison 2 Strength tests (all cancers), Outcome 2 Strength tests (all cancers: sensitivity analysis).
Figures and Tables -
Analysis 2.2

Comparison 2 Strength tests (all cancers), Outcome 2 Strength tests (all cancers: sensitivity analysis).

Table 1. Summary of included studies

Study

Exercise components

n

Meets Rock et al guidelines?

Adherence summary

At least 75% adherence?

High risk of bias?

Change in AET reported?

Adverse effects

Cadmus 2009

Aerobic

37, 38 (intervention vs control)

33% reported 150 minutes/wk of moderate intensity aerobic exercise at an average of 76% HR, for six months

75% of women were doing between 90 and 119 minutes of moderate intensity aerobic activity per week at six months

Yes; for up to 119 minutes per week

No

No

Five of the 37 women randomly assigned to exercise experienced an adverse effect; two were related to the study (plantar fasciitis)

Daley 2007a

Aerobic

34, 36, 38 (intervention,

sham, control, respectively)

No

77% of the exercise therapy; attended 70% (at least 17 of 24 sessions) or more of sessions

Unclear

Yes; outcome assessors were not blinded to participants’ group allocation

Yes

Three withdrawals in the intervention group: unclear as to why this occurred. Some withdrawals because of medical complications in placebo and control arms but unclear whether study related

Drouin 2005

Aerobic

13 intervention, 8 placebo stretching controls

Unclear

Participants in the intervention group averaged 3.6 days per week of aerobic exercise over an 8‐week period

Unclear

No

Yes

None reported

Kaltsatou 2011

Aerobic

14, 13 (intervention vs control)

Unclear

Not reported

Not reported

Yes; method of measuring exercise and adherence not reported

No

None reported

Kim 2006

Aerobic

22,19 (intervention vs control).

No

Average weekly frequency of exercise was 2.4 ± 0.6 sessions, and average duration of exercise within prescribed target HR was 27.8 ± 8.1 minutes per session. Overall adherence was 78.3% ± 20.1%

Yes

Yes; data missing for 45% of the cohort

Yes

Reasons for withdrawal included personal problems (n = 2), problems at home (n = 2), problems related to chemotherapy (n = 3), thrombophlebitis in the lower leg (n = 2), non-exercise‐related injuries (n = 1), and death (n = 1). Unclear to which arm of the trial these date relate

Pinto 2003

Aerobic

12, 12 (intervention vs

control)

Unclear

Participants attended a mean of 88% of the 36‐session supervised exercise programme

Yes

Yes; 38% lost to follow‐up. Exercise tolerance test was performed but no control group comparison data were reported

Yes

None reported; however, it is unclear why the six controls dropped out

Pinto 2005

Aerobic

43, 43 (intervention vs control)

Unclear

At week 12, intervention participants reported a mean of 128.53 minutes/wk of moderate intensity exercise. However, no changes were reported in the accelerometer data in the intervention group (change score = ‐0.33 kcal/h)

Less than 75% of the intervention group was meeting the prescribed goal after week 4

Yes; significantly more control group participants were receiving hormone treatment. Accelerometer data do not support the self‐reported physical activity behaviour

Yes

Not clear whether chest pain was related to exercise in dropout whose participation was terminated

Pinto 2011

Aerobic

20, 26 (intervention vs control)

Three‐day PAR questionnaire indicates that 64.7% of the intervention group and 40.9% of the control group were achieving the guidelines at three months

Correlation between self‐reported moderate intensity exercise and accelerometer data at three‐month follow‐up, when the only significant between‐group change is reported: r = 0.32

No

Yes; accelerometer data were not reported; also, cited correlation is weak (0.32). Further, substantial contamination was noted in the control group

Yes

One cancer recurrence in the control group at three months

Bourke 2011a

Aerobic and resistance

9, 9 (intervention vs control)

Six weeks of resistance exercise twice a week

90% attendance at the supervised sessions. 94% of independent exercise sessions were completed

Yes

No

Yes

One stroke in the intervention group, unrelated to the exercise programme

Bourke 2011b

Aerobic and resistance

25, 25 (intervention vs control)

Six weeks of resistance exercise twice a week

95% attendance at supervised exercise sessions. Compliance with self‐directed exercise aspect of the lifestyle intervention was 87%

Yes

Yes; high dropout rate at postintervention six‐month follow‐up assessment

Yes

Two men in the intervention arm were discontinued because of cardiac complications before the 12‐week assessments. Two more reported musculoskeletal complaints before the six‐month assessment. Five men reported various health problems in the control group that prohibited them from attending the six‐month assessment

Hayes 2009

Aerobic and resistance

16, 16 (intervention vs control)

Unclear

Most women (88%) allocated to the intervention group participated in 70% or more of scheduled supervised exercise sessions

Unclear

Yes; adherence data on unsupervised aspect of the intervention are not clear

No

None reported

McKenzie 2003

Aerobic and resistance

7,7 (intervention vs control)

No

Unclear

Unclear

Yes; adherence to exercise not reported

No

None reported

Musanti 2012

Aerobic and resistance

Flexibility group (n = 13), aerobic group (n = 12), resistance group (n = 17), aerobic and resistance group (n = 13)

12 weeks of resistance exercise two or three times per week

Mean percentages of adherence were as follows: flexibility = 85%, aerobic = 81%, resistance = 91% and aerobic plus resistance = 86%

Unclear

Yes; a significant number of dropouts belonged to the resistance exercise group (n = 8/13). Only 50% of activity logs were returned

Yes

Adverse effects were reported in two women during the study. In both cases, the women developed tendonitis: one in the shoulder and the other in the foot. Both had a history of tendonitis, and both received standard treatment

Perna 2010

Aerobic and resistance

51 participants in total. Numbers randomly assigned to each arm are unclear

Three months of resistance exercise three times per week

Women assigned to the structured intervention completed an average of 83% of their scheduled hospital‐based exercise sessions (only 4 weeks in duration), and 76.9% completed all 12 sessions. Home‐based component (8 weeks in duration)

Unclear

Yes; numbers randomly assigned to intervention and control groups are unclear, as are numbers completing in each arm

No

Unclear

AET = aerobic exercise tolerance.

Figures and Tables -
Table 1. Summary of included studies
Table 2. Behaviour change components

Behaviour change technique

Bourke 2011a

Bourke 2011b

Cadmus 2009

YALE

Daley 2007a

Drouin 2005

Hayes 2009

Kaltsatou 2011

McKenzie 2003

Musanti 2012

Perna 2010

Kim 2006

Pinto 2003

Pinto 2005

Pinto 2011

Theory

TTM

EXSEM

TTM

TTM

TTM SCT

1. Provide Info on consequences of behaviour in general

X

X

X

X

2. Provide Info on consequences of behaviour to the individual

3. Provide Info about others' approval

4. Provide normative info about others' behaviour

Programme set goal

X

X

X

X

X

X

X

X

X

X

X

X

X

X

5. Goal setting (behaviour)

X

X

X

X

X

X

6. Goal setting (outcome)

7. Action planning

8. Barrier identification/Problem solving

X

X

X

X

X

X

9. Setting of graded tasks

X

X

X

X

X

X

X

X

X

10. Prompt review of behavioural goals

X

X

11. Prompt review of outcome goals

12. Prompt rewards contingent on effort or progress towards goal

X

X

X

13. Provide rewards contingent on successful behaviour

X

14. Shaping

15. Prompt generalisation of a target behaviour

X

X

X

X

X

16. Prompt self‐monitoring of behaviour

X

X

X

X

X

X

X

X

X

X

17. Prompt self‐monitoring of behavioural outcome

X

X

X

X

X

X

18. Prompt focus on past success

X

19. Feedback on performance provided

X

X

X

X

20. Information provided on where and when to perform behaviour

X

X

21. Instruction provided on how to perform the behaviour

X

X

X

X

X

X

X

X

X

X

22. Modelling/Demonstration of behaviour

X

X

X

23. Teaching to use prompts/cues

X

X

X

24. Environmental restructuring

X

X

25. Agreement on behavioural contract

X

26. Prompt practise

X

X

X

X

X

X

X

X

X

X

X

X

X

X

27. Use of follow‐up prompts

X

X

28. Facilitating social comparison

29. Planning social support/social change

X

X

X

30. Prompt identification as role model/position advocate

31. Prompt anticipated regret

32. Fear arousal

33. Prompt self‐talk

34. Prompt use of imagery

35. Relapse prevention/coping planning

X

X

36. Stress management/emotional control training

X

37. Motivational interviewing

38. Time management

39. General communication skills training

40. Stimulation of anticipation of future rewards

EXSEM = exercise self‐esteem model; SCT = social cognitive theory; TTM = transtheroretical model.

Figures and Tables -
Table 2. Behaviour change components
Comparison 1. Aerobic exercise tolerance

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Aerobic exercise tolerance (all cancers: 8 to 12 weeks of follow‐up) Show forest plot

7

330

Std. Mean Difference (IV, Fixed, 95% CI)

0.73 [0.51, 0.95]

2 Aerobic exercise tolerance (all cancers: 8 to 12 weeks of follow‐up sensitivity analysis) Show forest plot

3

154

Std. Mean Difference (IV, Fixed, 95% CI)

0.84 [0.51, 1.17]

3 Aerobic exercise tolerance (all cancers: 6 months) Show forest plot

5

271

Std. Mean Difference (IV, Fixed, 95% CI)

0.70 [0.45, 0.94]

Figures and Tables -
Comparison 1. Aerobic exercise tolerance
Comparison 2. Strength tests (all cancers)

Outcome or subgroup title

No. of studies

No. of participants

Statistical method

Effect size

1 Strength tests Show forest plot

3

91

Std. Mean Difference (IV, Fixed, 95% CI)

0.51 [0.09, 0.93]

2 Strength tests (all cancers: sensitivity analysis) Show forest plot

2

68

Std. Mean Difference (IV, Fixed, 95% CI)

0.47 [‐0.01, 0.96]

Figures and Tables -
Comparison 2. Strength tests (all cancers)