Differences in post-operative infection rates between patients receiving autologous and allogeneic blood transfusion: a meta-analysis of published randomized and nonrandomized studies.

We have undertaken a meta-analysis of the post-operative infection rates in patients who received autologous blood compared with allogeneic blood. Nine studies published after 1989 were identified, of which seven had sufficient data on transfusion given in the paper to be included, giving a total of 1060 patients. The risk of post-operative infection was greater in the allogeneic group, odds ratio 2.37 (95% confidence interval (CI) 1.6-3.6, P < 0.0001) compared with the autologous group. Allogeneic and autologous blood transfusion should be compared in a large multicentre randomized control trial.