Associations of health status with subsequent blood donor behavior—An alternative perspective on the Healthy Donor Effect from Donor InSight

Abstract

IntroductionIn donor health research, the ‘Healthy Donor Effect’ (HDE) often biases study results and hampers their interpretation. This refers to the fact that donors are a selected ‘healthier’ subset of a population due to both donor selection procedures and self-selection. Donors with long versus short donor careers, or with high versus low donation intensities are often compared to avoid this HDE, but underlying health differences might also cause these differences in behaviour. Our aim was to estimate to what extent a donor´s perceived health status associates with donation cessation and intensity.MethodsAll active whole blood donors participating in Donor InSight (2007–2009; 11,107 male; 12,616 female) were included in this prospective cohort study. We performed Cox survival and Poisson regression analyses to assess whether self-reported health status, medication use, disease diagnosed by a physician and recently having consulted a general practitioner (GP) or specialist were associated with (time to) donation cessation and donation intensity.ResultsAt the end of 2013, 44% of the donors in this study had stopped donating. Donors in self-rated good health had a 15% lower risk to stop donating compared to donors in perceived poorer health. Medication use, disease diagnoses and consulting a GP were associated with a 20–40% increased risk to stop donating and a lower donation intensity, when adjusting for age, number of donations and new donor status. Both men and women reporting good health made on average 10% more donations.ConclusionDonors with a “good” health status were less likely to stop donating blood and tended to donate blood more often than donors with perceived poorer health status. This implies that the HDE is an important source of selection bias in studies on donor health and this includes studies where comparisons within donors are made. This HDE should be adjusted for appropriately when assessing health effects of donation and donors’ health status may provide estimates of future donation behavior.

Iron supplementation by blood donors: demographics, patterns of use, and motivation

“…This finding needs careful interpretation, since our analysis was on the donation level, and since the NHANES analyses did not stratify age categories by sex, and we found differing age associations among women and men . The design of NHANES also differs from our study in that NHANES uses a multitiered sampling frame allowing for derivation of representative estimates for the US population, whereas blood donors represent a convenience sample widely recognized as healthier than the general population . Further, NHANES was conducted by on‐site visits, where dietary supplement containers were analyzed by trained interviewers rather than by self‐reporting at a blood drive.…”

The alteration of ferritin and transferrin saturation under body mass index and blood pressure in first-time and regular male blood donors in Taiwan

“…Donors with perceived good health status tend to donate blood more often than donors with perceived poor health status. [18]…”

The association between population density and blood lipid levels in Dutch blood donors

“…There are, however, other possible explanations as to why no association was found between population density and blood lipid levels. Our study population was relatively healthy, with respect to both blood lipid levels and physical activity, which is probably the result of donor selection based on eligibility criteria and self-selection [53–56]. Beneficial effects of repeated blood donation on blood lipid profiles have been suggested in the literature [57, 58].…”