Iron therapy for pre‐operative anaemia

Oliver Ng; Barrie D Keeler; Amitabh Mishra; Alastair Simpson; Keith Neal; Matthew J Brookes; Austin G Acheson

doi:10.1002/14651858.CD011588.pub2

Liječenje preoperativne anemije željezom

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Referencias

References to studies included in this review

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estudios excluidos
otras referencias

Noble E, Edwards T, Durran A, Mellor N, Hosie KB. A prospective blinded placebo controlled randomised trial of intravenous iron supplementation in patients undergoing colorectal cancer surgery. Colorectal disease 2009;Conference: Association of Coloproctology of Great Britain and Ireland Annual Meeting Harrogate United Kingdom. Conference Start: 20090608 Conference End: 20090611. Conference Publication:(Supplement S1):31.

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Kim YH, Chung HH, Kang S‐B, Kim SC, Kim YT. Safety and usefulness of intravenous iron sucrose in the management of preoperative anemia in patients with menorrhagia: a phase IV, open‐label, prospective, randomised study. Acta Haematologica 2009;121(1):37‐41.

Lidder PG, Sanders G, Whitehead E, Douie WJ, Mellor N, Lewis SJ, et al. Pre‐operative oral iron supplementation reduces blood transfusion in colorectal surgery ‐ a prospective, randomised, controlled trial. Annals of the Royal College of Surgeons of England 2007;89(4):418‐21.

References to studies excluded from this review

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estudios incluidos
otras referencias

Andrews CM, Lane DW, Bradley JG. Iron pre‐load for major joint replacement. Transfusion Medicine (Oxford, England) 1997;7(4):281‐6.

Crosby L, Palarski VA, Cottington E, Cmolik B. Iron supplementation for acute blood loss anemia after coronary artery bypass. Heart & Lung: The Journal of Acute and Critical Care 1994;23(6):493‐9.

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Garrido‐Martin P, Nassar‐Mansur MI, de la Llana‐Ducros R, Virgos‐Aller TM, Rodriguez Fortunez PM, Avalos‐Pinto R, et al. The effect of intravenous and oral iron administration on perioperative anaemia and transfusion requirements in patients undergoing elective cardiac surgery: A randomized clinical trial. Interactive Cardiovascular and Thoracic Surgery 2012;15(6):1013‐8.

Additional references

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estudios incluidos
estudios excluidos

Anker SD, Comin Colet J, Filippatos G, Willenheimer R, Dickstein K, Drexler H, et al. Ferric carboxymaltose in patients with heart failure and iron deficiency. New England Journal of Medicine 2009;361:2436‐48. [PUBMED: 19920054]

Auerbach M, Ballard H. Clinical use of intravenous iron: administration, efficacy, and safety. Hematology. American Society of Hematology Education Program 2010;2010(1):338‐47. [PUBMED: 21239816]

Benoist S, Panis Y, Pannegeon V, Alves A, Valleur P. Predictive factors for perioperative blood transfusions in rectal resection for cancer: A multivariate analysis of a group of 212 patients. Surgery 2001;129(4):433‐9. [PUBMED: 11283534]

Breymann C, Gliga F, Bejenariu C, Strizhova N. Comparative efficacy and safety of intravenous ferric carboxymaltose in the treatment of postpartum iron deficiency anemia. International Journal of Gynaecology and Obstetrics 2008;101(1):67‐73. [PUBMED: 18234203]

Carson JL, Duff A, Poses RM, Berlin JA, Spence RK, Trout R, et al. Effect of anaemia and cardiovascular disease on surgical mortality and morbidity. Lancet 1996;348(9034):1055‐60. [PUBMED: 8874456]

Chertow GM, Mason PD, Vaage‐Nilsen O, Ahlmén J. On the relative safety of parenteral iron formulations. Nephrology Dialysis Transplantation 2004;19(6):1571‐5.

Cuenca J, Garcia‐Erce JA, Munoz M, Izuel M, Martinez AA, Herrera A. Patients with pertrochanteric hip fracture may benefit from preoperative intravenous iron therapy: a pilot study. Transfusion 2004;44(10):447‐52. [PUBMED: 15383017]

Cuenca J, Garcia‐Erce JA, Martínez AA, Solano VM, Molina J, Muñoz M. Role of parenteral iron in the management of anaemia in the elderly patient undergoing displaced subcapital hip fracture repair: preliminary data. Archives of Orthopaedic and Trauma Surgery 2005;125(5):342–7.

Dunne JR, Malone D, Tracy JK, Gannon C, Napolitano LM. Perioperative anemia: an independent risk factor for infection, mortality, and resource utilization in surgery. Journal of Surgical Research 2002;102(2):237‐44. [PUBMED: 11796024]

Garcia‐Erce JA, Cuenca J, Munoz M, Izuel M, Martinez AA, Herrera A, et al. Perioperative stimulation of erythropoiesis with intravenous iron and erythropoietin reduces transfusion requirements in patients with hip fracture. A prospective observational study. Vox Sanguinis 2005;88(4):235‐43. [PUBMED: 15877644]

Heath CW, Strauss MB, Castle WB. Quantitative aspects of iron deficiency in hypochromic anaemia (The parenteral administration of iron). Journal of Clinical Investigation 1932;11(16):1293‐312. [PUBMED: PMC435880]

Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Keeler BK, Simpson JA, Ng O, Padmanabhan H, Brookes MJ, Acheson AG, et al. An open‐label, randomised controlled trial comparing the efficacy of intravenous and oral iron in the preoperative management of colorectal cancer anaemia: IVICA trial. Gut. 2015; Vol. 64:A339, Abstract PWE‐290. [DOI: 10.1136/gutjnl‐2015‐309861.736]

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Kulnigg S, Stoinov S, Simanenkov V, Dudar LV, Karnafel W, Garcia LC, et al. A novel intravenous iron formulation for treatment of anemia in inflammatory bowel disease: the ferric carboxymaltose (FERINJECT) randomized controlled trial. American Journal of Gastroenterology 2008;103(5):1182‐92. [PUBMED: 18371137]

Lefebvre C, Manheimer E, Glanville J. Chapter 6: Searching for studies. In: Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions. Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from www.cochrane‐handbook.org.

Leichtle SW, Mouawad NJ, Lampman R, Singal B, Cleary RK. Does preoperative anemia adversely affect colon and rectal surgery outcomes?. Journal of the American College of Surgeons 2011;212(2):187‐94. [PUBMED: 21276532]

Munoz M, Villar I, Garcia‐Erce JA. An update on iron physiology. World Journal of Gastroenterology 2009;15(37):4617‐26. [PUBMED: PMC2754509]

Okonko DO, Grzeslo A, Witkowski T, Mandal AK, Slater RM, Roughton M, et al. Effect of intravenous iron sucrose on exercise tolerance in anemic and nonanemic patients with symptomatic chronic heart failure and iron deficiency FERRIC‐HF: a randomized, controlled, observer‐blinded trial. Journal of the American College of Cardiology 2008;51(2):103‐12. [PUBMED: 18191732]

Okuyama M, Ikeda K, Shibata T, Tsukahara Y, Kitada M, Shimano T. Preoperative iron supplementation and intraoperative transfusion during colorectal cancer surgery. Surgery Today 2005;35(1):36‐40.

Perkins S. Diagnosis of Anemia. In: Kjeldsberg CR editor(s). Practical Diagnosis of Hematologic Disorders. 4th Edition. Chicago: ASCP Press, 2006.

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Piednoir P, Allou N, Driss F, Longrois D, Philip I, Beaumont C, et al. Preoperative iron deficiency increases transfusion requirements and fatigue in cardiac surgery patients: a prospective observational study. European Journal of Anaesthesiology 2011;28(11):796‐801. [PUBMED: 21885979]

Quinn M, Drummond RJ, Ross F, Murray J, Murphy J, Macdonald A. Short course pre‐operative ferrous sulphate supplementation ‐ is it worthwhile in patients with colorectal cancer?. Annals of The Royal College of Surgeons of England 2010;92(7):569‐72. [PUBMED: 20573311]

Qunibi WY, Martinez C, Smith M, Benjamin J, Mangione A, Roger SD. A randomized controlled trial comparing intravenous ferric carboxymaltose with oral iron for treatment of iron deficiency anaemia of non‐dialysis‐dependent chronic kidney disease patients. Nephrology Dialysis Transplantation 2011;26(5):1599‐607. [PUBMED: 20929915]

The Nordic Cochrane Centre, The Cochrane Collaboration. Review Manager (RevMan). Version 5.3. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014.

Seid MH, Derman RJ, Baker JB, Banach W, Goldberg C, Rogers R. Ferric carboxymaltose injection in the treatment of postpartum iron deficiency anemia: a randomized controlled clinical trial. American Journal of Obstetrics and Gynecology 2008;199:435 e1‐7. [PUBMED: 18928998]

Shander A, Knight K, Thurer R, Adamson J, Spence R. Prevalence and outcomes of anemia in surgery: a systematic review of the literature. American Journal of Medicine 2004;116(Suppl 7A):58S‐69S. [PUBMED: 15050887]

Spahn DR. Anemia and patient blood management in hip and knee surgery: a systematic review of the literature. Anesthesiology 2010;113(2):482‐95. [PUBMED: 20613475]

Swain RA, Kaplan B, Montgomery E. Iron deficiency anemia. When is parenteral therapy warranted?. Postgraduate Medical Journal 1996;100(5):181‐2, 185, 188‐93. [PUBMED: 8917332]

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Varat MA, Adolph RJ, Fowler NO. Cardiovascular effects of anemia. American Heart Journal 1972;83(3):415‐26.

Characteristics of studies

Characteristics of included studies [ordered by study ID]

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estudios excluidos

Edwards 2009

Methods	Prospective randomised blinded placebo‐control trial.
Participants	Pre‐operative patients undergoing surgery for colorectal cancer (n = 60; note only 18 patients anaemic).
Interventions	IV iron sucrose 600 mg in 2 doses versus placebo.
Outcomes	Transfusion rates and amount of blood transfused, recruitment and admission haemoglobin.
Notes	Study has only 9 anaemic patients in each arm of whom many were not iron deficient.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "allocated to either the treatment (iron) group or a placebo group, based on a computer‐generated randomisation sequence provided by the Research and Development Support Unit. To ensure equal numbers of anaemic patients in each treatment group, randomisation was stratified according to pre‐recruitment Hb status: normal (Hb level at least 13.5 g/dL in males and 12/5 g/dL in females), anaemic, or unknown (no test within 2 months of recruitment). Block randomisation was used to ensure similar numbers in each group for each subset."
Allocation concealment (selection bias)	Low risk	Quote: "Allocation codes were sealed in sequentially numbered opaque envelopes which were secured within a locked store room in a dedicated research unit."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "Although the investigator administering the infusion was not blinded to the treatment group, this was concealed from the patient by using an opaque sheath to cover the drug‐giving set."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "The chief investigator and clinicians involved in perioperative care also remained blinded to the treatment group for the duration of the trial."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: It appears there was no loss to follow up among people with anaemia.
Selective reporting (reporting bias)	Unclear risk	Comment: None identified.
Other bias	Unclear risk	Comment: None identified.

Kim 2009

Methods	Prospective randomised control trial, open label.
Participants	Anaemic pre‐operative patients with menorrhagia who were due to undergo surgery (n = 76; note only 56 patients > 80% compliance are included in analysis, Hb < 90 g/L).
Interventions	IV iron sucrose (dose according to Ganzoni’s formula for cumulative iron deficit) versus oral iron succinylate (dose 80 mg per day for 3 weeks).
Outcomes	Recruitment and admission haemoglobin.
Notes	The study took place between December 2005 and January 2007.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "computer‐generated randomisation table... [to] randomly assign patients."
Allocation concealment (selection bias)	Low risk	Quote: "Group allocation was determined by one of the authors not directly involved in patient care."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Comment: Open label study, no blinding but unlikely to influence the change in haemoglobin.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Comment: No blinding but objective measurement of haemoglobin unlikely to be influenced.
Incomplete outcome data (attrition bias) All outcomes	High risk	Quote: "Participants who had > 80% compliance were included in the analysis" Comment: Not analysed on intention‐to‐treat basis. Important because oral iron has reportedly poor tolerance and therefore poor compliance.
Selective reporting (reporting bias)	Unclear risk	Comment: None identified.
Other bias	Unclear risk	Comment: None identified.

Lidder 2007

Methods	Prospective randomised control trial.
Participants	Pre‐operative patients undergoing surgery for colorectal cancer (n = 49; note only 20 patients anaemic).
Interventions	Oral ferrous sulphate 200 mg TDS versus standard care.
Outcomes	Transfusion rates and amount of blood transfused, pre‐treatment and pre‐operative haemoglobin.
Notes	Did not exclude non‐anaemic patients.
*Risk of bias*
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: Study does not explain how randomisation was achieved.
Allocation concealment (selection bias)	Unclear risk	Quote: "patients were randomised (by telephone to a distant centre)."
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "The clinical team (surgeons, nurses, anaesthetists) were blinded to treatment allocation. It was not possible to use a placebo and blind the patient, as oral iron alters stool colour."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "The collection of data was performed by a research fellow not involved in the direct care of the patient."
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Quote: "Two patients from each group were deemed unsuitable for resective surgery at admission, two underwent stent insertion and two were referred to the palliative care team." Comment: No incomplete outcome data was reported.
Selective reporting (reporting bias)	Unclear risk	Comment: None identified.
Other bias	Unclear risk	Comment: None identified.

Characteristics of excluded studies [ordered by study ID]

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estudios incluidos

Study	Reason for exclusion
Andrews 1997	Not a randomised controlled trial. All anaemic patients given iron therapy with no control arm. Non‐anaemic patients were randomised but since they did not have pre‐operative anaemia this study is excluded from the review.
Crosby 1994	Study included all patients, anaemic and non‐anaemic, and has not stratified results to allow analysis of only those patients with pre‐operative anaemia.
Garrido‐Martin 2012	Study specifically excluded patients with previous anaemia therefore no patients in this study had pre‐operative anaemia.

Data and analyses

Open in table viewer

Comparison 1. Iron therapy versus placebo or no iron therapy

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Proportion of patients who received a blood transfusion Show forest plot	2	38	Risk Ratio (M‐H, Fixed, 95% CI)	0.56 [0.27, 1.18]
Open in figure viewer Analysis 1.1 Comparison 1 Iron therapy versus placebo or no iron therapy, Outcome 1 Proportion of patients who received a blood transfusion.
2 Haemoglobin levels pre‐treatment (g/dL) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.2 Comparison 1 Iron therapy versus placebo or no iron therapy, Outcome 2 Haemoglobin levels pre‐treatment (g/dL).
3 Haemoglobin levels at end of treatment pre‐op (g/dL) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.3 Comparison 1 Iron therapy versus placebo or no iron therapy, Outcome 3 Haemoglobin levels at end of treatment pre‐op (g/dL).
4 Haemoglobin levels after treatment post‐op (g/dL) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected
Open in figure viewer Analysis 1.4 Comparison 1 Iron therapy versus placebo or no iron therapy, Outcome 4 Haemoglobin levels after treatment post‐op (g/dL).

Open in table viewer

Comparison 2. Iron therapy: Intravenous versus oral administration

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Haemoglobin level pre‐treatment (g/dL) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
Open in figure viewer Analysis 2.1 Comparison 2 Iron therapy: Intravenous versus oral administration, Outcome 1 Haemoglobin level pre‐treatment (g/dL).
2 Haemoglobin level post‐treatment pre‐op (g/dL) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
Open in figure viewer Analysis 2.2 Comparison 2 Iron therapy: Intravenous versus oral administration, Outcome 2 Haemoglobin level post‐treatment pre‐op (g/dL).
3 Ferritin level pre‐treatment (ɥg/L) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
Open in figure viewer Analysis 2.3 Comparison 2 Iron therapy: Intravenous versus oral administration, Outcome 3 Ferritin level pre‐treatment (ɥg/L).
4 Ferritin level post‐treatment (ɥg/L) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
Open in figure viewer Analysis 2.4 Comparison 2 Iron therapy: Intravenous versus oral administration, Outcome 4 Ferritin level post‐treatment (ɥg/L).

Figure 1

Study flow diagram.

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Figure 2

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

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Figure 3

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

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Analysis 1.1

Comparison 1 Iron therapy versus placebo or no iron therapy, Outcome 1 Proportion of patients who received a blood transfusion.

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Analysis 1.2

Comparison 1 Iron therapy versus placebo or no iron therapy, Outcome 2 Haemoglobin levels pre‐treatment (g/dL).

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Analysis 1.3

Comparison 1 Iron therapy versus placebo or no iron therapy, Outcome 3 Haemoglobin levels at end of treatment pre‐op (g/dL).

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Analysis 1.4

Comparison 1 Iron therapy versus placebo or no iron therapy, Outcome 4 Haemoglobin levels after treatment post‐op (g/dL).

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Analysis 2.1

Comparison 2 Iron therapy: Intravenous versus oral administration, Outcome 1 Haemoglobin level pre‐treatment (g/dL).

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Analysis 2.2

Comparison 2 Iron therapy: Intravenous versus oral administration, Outcome 2 Haemoglobin level post‐treatment pre‐op (g/dL).

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Analysis 2.3

Comparison 2 Iron therapy: Intravenous versus oral administration, Outcome 3 Ferritin level pre‐treatment (ɥg/L).

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Analysis 2.4

Comparison 2 Iron therapy: Intravenous versus oral administration, Outcome 4 Ferritin level post‐treatment (ɥg/L).

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Summary of findings for the main comparison. Iron therapy versus placebo or no iron therapy for pre‐operative anaemia

Iron therapy versus placebo or no iron therapy for pre‐operative anaemia
Patient or population: Patients with pre‐operative anaemia Settings: Major surgery Intervention: Iron therapy versus placebo or no iron therapy
Outcomes	*Illustrative comparative risks (95% CI)**		Relative effect (95% CI)	No of Participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Control	Iron therapy
Proportion of patients who received a blood transfusion	635 per 1000	356 per 1000 (171 to 749)	RR 0.56 (0.27 to 1.18)	38 (2 studies)	⊕⊕⊝⊝ low¹
Amount of blood transfused per patient (in units)	Data from two small studies could not be combined as they were skewed and reported as medians and ranges. One RCT in 18 people reported a difference in medians of 0 (interquartile range: 1) with iron therapy. Another RCT in 20 people reported a median difference of 1 unit with iron therapy (range 0 to 2).		‐	38 (2 studies)	⊕⊕⊝⊝ low¹	It is not possible to combine the data because they are skewed. These are the raw data.
Post‐operative mortality	‐	‐	‐	‐	‐	This outcome was not reported in either of the two studies available.
Post‐operative morbidity	‐	‐	‐	‐	‐	This outcome was not reported in either of the two studies available.
Any validated measure of quality of life	‐	‐	‐	‐	‐	This outcome was not reported in either of the two studies available.
Haemoglobin levels at end of treatment pre‐op (g/dL)	mean 11.9 g/dL (SD 2.6)	mean 11.2 g/d L(SD 1.95)	The mean haemoglobin levels at end of treatment pre‐op (g/dl) in the intervention groups was 0.7 g/dL lower (2.82 lower to 1.42 higher)	18 (1 study)	⊕⊕⊝⊝ low²	Data from one study; the raw data are presented.
The basis for the assumed risk* (e.g. the median control group risk across studies) is provided in footnotes. 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; RR: Risk ratio; MD: mean difference; g/dL: grams per decilitre of blood.
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 Only two small randomised control trials and a subset of anaemic patients resulting in a very small number of participants. ² Only one study with a small number of participants available.

Summary of findings for the main comparison. Iron therapy versus placebo or no iron therapy for pre‐operative anaemia

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Summary of findings 2. Iron therapy: Intravenous versus oral administration for pre‐operative anaemia

Iron therapy: Intravenous versus oral administration for pre‐operative anaemia
Patient or population: Patients with pre‐operative anaemia Settings: Major surgery Intervention: Iron therapy: Intravenous versus oral administration
Outcomes	*Illustrative comparative risks (95% CI)**		Relative effect (95% CI)	No of Participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Oral iron therapy	Intravenous iron therapy
Proportion of patients who received a blood transfusion	‐	‐	‐	‐	‐	This outcome was not reported in the one study available.
Amount of blood transfused per patient (in units)	‐	‐	‐	‐	‐	This outcome was not reported in the one study available.
Post‐operative mortality	‐	‐	‐	‐	‐	This outcome was not reported in the one study available.
Post‐operative morbidity	‐	‐	‐	‐	‐	This outcome was not reported in the one study available.
Any validated measure of quality of life	‐	‐	‐	‐	‐	This outcome was not reported in the one study available.
Haemoglobin levels at end of treatment pre‐op (g/dL)	mean 8.6 g/dL (SD 1.4)	mean 10.5 g/dL (SD 1.4)	The mean haemoglobin levels at end of treatment pre‐op (g/dl) in the intravenous group was 1.9 g/dL higher (1.16 to 2.64 higher)	56 (1 study)	⊕⊕⊝⊝ low^1,2
The basis for the assumed risk* (e.g. the median control group risk across studies) is provided in footnotes. 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). g/dL: grams per decilitre of blood.
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 Study excluded those with less than 80% compliance with therapy and compliance was lower in the oral administration group. ² Only one study with a small number of participants.

Summary of findings 2. Iron therapy: Intravenous versus oral administration for pre‐operative anaemia

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Comparison 1. Iron therapy versus placebo or no iron therapy

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Proportion of patients who received a blood transfusion Show forest plot	2	38	Risk Ratio (M‐H, Fixed, 95% CI)	0.56 [0.27, 1.18]

2 Haemoglobin levels pre‐treatment (g/dL) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

3 Haemoglobin levels at end of treatment pre‐op (g/dL) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

4 Haemoglobin levels after treatment post‐op (g/dL) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Totals not selected

Comparison 1. Iron therapy versus placebo or no iron therapy

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Comparison 2. Iron therapy: Intravenous versus oral administration

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Haemoglobin level pre‐treatment (g/dL) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only

2 Haemoglobin level post‐treatment pre‐op (g/dL) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only

3 Ferritin level pre‐treatment (ɥg/L) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only

4 Ferritin level post‐treatment (ɥg/L) Show forest plot	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only

Comparison 2. Iron therapy: Intravenous versus oral administration

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Referencias

References to studies included in this review

Edwards 2009 {published data only}

Kim 2009 {published data only}

Lidder 2007 {published data only}

References to studies excluded from this review

Andrews 1997 {published data only}

Crosby 1994 {published data only}

Garrido‐Martin 2012 {published data only}

Additional references

Anker 2009

Auerbach 2010

Benoist 2001

Breymann 2008

Carson 1996

Chertow 2004

Cuenca 2004

Cuenca 2005

Dunne 2002

Garcia‐Erce 2005

Heath 1932

Higgins 2011

Keeler 2015

Kulnigg 2008

Lefebvre 2011

Leichtle 2011

Munoz 2009

Okonko 2008

Okuyama 2005

Perkins 2006

Piednoir 2011

Quinn 2010

Qunibi 2011

Review Manager 2014 [Computer program]

Seid 2008

Shander 2004

Spahn 2010

Swain 1996

Vamvakas 2009

Varat 1972

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Characteristics of excluded studies [ordered by study ID]

Data and analyses

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