A Cochrane review included 4 studies with a total of 462 subjects. There were no statistically significant differences in the proportion of patients transfused between the erythropoietin group and control group (RR 0.92, 95% CI 0.65 to 1.31, 3 studies). 1 of the studies showed a small difference in the median number of units transfused per patient favouring treatment. There were no significant differences in post-operative mortality (RR 2.12, 95% CI 0.59 to 7.65; 2 studies) or thrombotic events (RR 1.71, 95% CI 0.41 to 7.08) between the treatment and control groups. No included study evaluated recurrences, survival, or quality of life.
Comment: The quality of evidence is downgraded by study quality (inadequate or unclear allocation concealment and inadequate intention-to-treat adherence), by indirectness (short duration and low dose of intervention) and by imprecise results (limited study size for each comparison).