BACKGROUND: Each year, approximately 5% of the invited blood donors is eventually deferred from donation because of low hemoglobin (Hb) levels. Estimating the risk of Hb deferral in blood donors can be helpful in the management of the donation program. We developed and validated a prediction model for Hb deferral in whole blood donors, separately for men and women.

STUDY DESIGN AND METHODS: Data from a Dutch prospective cohort of 220,946 whole blood donors were used to identify predictors for Hb deferral using multivariable logistic regression analyses. Validity of the prediction models was assessed with a cross-validation.

RESULTS: A total of 12,865 donors (5.8%) were deferred because of a low Hb level. The strongest predictors of Hb deferral were Hb level measured at the previous visit, age, seasonality, difference in Hb levels between the previous two visits, time since the previous visit, deferral at the previous visit, and the total number of whole blood donations in the past 2 years for both men and women. The prediction models had an area under the receiver operating characteristic curve of 0.89 for men and 0.84 for women. Cross-validation showed similar results and good calibration.

CONCLUSION: Using a limited number of easy-to-measure characteristics enables a good prediction of Hb deferral risk in whole blood donors. The prediction models may guide the decision which donors to invite for a next donation and for which donors the invitation should be postponed. Potentially, this could decrease the number of Hb deferrals in blood donors.