Deferral due to low hemoglobin and predictors of permanence in the blood donation system of repeat female blood donors.

OBJECTIVES

To evaluate the deferral rate due to low hemoglobin (Hb) in repeat female blood donors and identify the factors affecting their permanence in the blood donation system.

MATERIALS AND METHODS

8,368 repeat female blood donors who donated from January 2012 to December 2018 were included. Bivariate analysis and Kaplan-Meier curves were used to identify the covariates possibly associated with developing low Hb, and Cox proportional hazards modeling was used to adjust for all confounders.

RESULTS

The global deferral rate due to low Hb was 2.4 %. According to baseline Hb, the frequency of low Hb was 0.7-4.1 %, and it was higher in platelet donors (5.8-9.1 %) than in whole blood donors (1.9 %). The main predictors were baseline Hb (compared to the first quartile; hazard ratio [HR] = 0.487 for the second quartile; 0.234 for the third; and 0.095 for the fourth); change in Hb (HR = 2.689 for a >0.49 g/dL change, compared to smaller changes); the type of donation (compared to whole blood donors, HR = 2.317 for platelet donors); and donation interval (compared to >12.5 month intervals; HR = 2.220 for 8.0-12.5 months; HR = 5.658 for 5.4-8.0 months; and HR = 9.452 for <5.4 months).

CONCLUSIONS

In female blood donors at moderate altitude, the probability of developing low Hb increases with a baseline Hb of 13.5-14.0 g/dL, with a change in Hb >0.49 g/dL, in platelet donors, and with donation intervals <12.5 months. These four predictive factors can be used together for early identification of donors at risk of developing low Hb, to institute appropriate measures.