Adjusted probability of overall survival in 701 adult MDS patients by donor source. In multivariate analysis, the risk of all-cause mortality was significantly higher with 7 of 8 MUD HCT recipients compared with MRD and 8 of 8 MUD HCT recipients (RR 1.62 [95% CI 1.21-2.17] and 1.30 [95% CI 1.01-1.68], respectively). The risk was not different between 8 of 8 MUD and MRD HCT recipients (RR 1.24, 95% CI 0.98-1.56).