What population factors influence the decision to donate blood?

Donations of blood in most of the developed world are by nonremunerated volunteers. As such factors, which impact upon the motivation of individuals to donate, are critical to achieving a stable supply, we analyze the factors, which influence the decision to donate. Using data on 130,356 corrected individuals from 1999 and 2000, we investigate which factors determine the proportion of blood donors in postcode areas. Variables analyzed include blood donation status and sociodemographic characteristics in order to provide information on donation decisions. We find the proportion of donors in an area is significantly increased by higher proportions of women aged 20-29 and 40-49, and of men aged 60-69. Conversely, a higher proportion of males aged 20-29 significantly reduces proportion of donors. Also, a higher proportion of individuals born overseas significantly reduces the proportion of blood donors in an area. To increase supplies, blood collection agencies should target specific groups. Young men and men and women aged 30-49 need to be encouraged to donate. Collection agencies also need to target individuals who are born overseas to participate in the process. Using these results to aid targeting should help to maintain the blood supply.