ANALYSIS OF BLOOD-DONOR RETURN BEHAVIOR USING SURVIVAL REGRESSION METHODS

The acquisition of a sufficient and safe supply of blood products is r equired to support medical care; in most countries this has a reliance on voluntary, nonremunerated donors. Recent reported shortages in the States and elsewhere have highlighted the need for a method to measur e and evaluate blood donor return behaviour. This paper describes a fr amework within which standard time-to-outcome methods can be used to a nalyse blood donor return behaviour. Survival curves and relative risk estimates derived from a proportional hazards analysis of a large adm inistrative dataset are reported. In addition to assessing the effect of sex, age and other key donor demographic factors on the probability of a subsequent donation attempt, the analysis reveals that the relat ive risks are time-dependent. This suggests that the likelihood of att empting a subsequent donation may also depend on the time since the in dex donation attempt. The implications for blood collection agencies a nd transfusion researchers of this new perspective on donor behaviour are discussed.