Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2015 Oct;102(11):1314-24.
doi: 10.1002/bjs.9861.

Meta-analysis of the Association Between Preoperative Anaemia and Mortality After Surgery

Affiliations
Review

Meta-analysis of the Association Between Preoperative Anaemia and Mortality After Surgery

A J Fowler et al. Br J Surg. .

Abstract

Background: Numerous published studies have explored associations between anaemia and adverse outcomes after surgery. However, there are no evidence syntheses describing the impact of preoperative anaemia on postoperative outcomes.

Methods: A systematic review and meta-analysis of observational studies exploring associations between preoperative anaemia and postoperative outcomes was performed. Studies investigating trauma, burns, transplant, paediatric and obstetric populations were excluded. The primary outcome was 30-day or in-hospital mortality. Secondary outcomes were acute kidney injury, stroke and myocardial infarction. Predefined analyses were performed for the cardiac and non-cardiac surgery subgroups. A post hoc analysis was undertaken to evaluate the relationship between anaemia and infection. Data are presented as odds ratios (ORs) with 95 per cent c.i.

Results: From 8973 records, 24 eligible studies including 949 445 patients were identified. Some 371 594 patients (39·1 per cent) were anaemic. Anaemia was associated with increased mortality (OR 2·90, 2·30 to 3·68; I(2) = 97 per cent; P < 0·001), acute kidney injury (OR 3·75, 2·95 to 4·76; I(2) = 60 per cent; P < 0·001) and infection (OR 1·93, 1·17 to 3·18; I(2) = 99 per cent; P = 0·01). Among cardiac surgical patients, anaemia was associated with stroke (OR 1·28, 1·06 to 1·55; I(2) = 0 per cent; P = 0·009) but not myocardial infarction (OR 1·11, 0·68 to 1·82; I(2) = 13 per cent; P = 0·67). Anaemia was associated with an increased incidence of red cell transfusion (OR 5·04, 4·12 to 6·17; I(2) = 96 per cent; P < 0·001). Similar findings were observed in the cardiac and non-cardiac subgroups.

Conclusion: Preoperative anaemia is associated with poor outcomes after surgery, although heterogeneity between studies was significant. It remains unclear whether anaemia is an independent risk factor for poor outcome or simply a marker of underlying chronic disease. However, red cell transfusion is much more frequent amongst anaemic patients.

Similar articles

See all similar articles

Cited by 34 articles

See all "Cited by" articles

LinkOut - more resources

Feedback