Estimates of infectious disease risk factors in US blood donors. Retrovirus Epidemiology Donor Study
A. E. Williams, R. A. Thomson, G. B. Schreiber, K. Watanabe, J. Bethel, A. Lo, S. H. Kleinman, C. G. Hollingsworth and G. J. Nemo
American Red Cross Blood Services, Holland Laboratory, Rockville, MD 20855, USA.
OBJECTIVE: Individuals who do not respond accurately to questions about
infectious disease risk factors at the time of blood donation represent a
potential threat to the safety of the blood supply. This study was designed
to estimate the prevalence of undetected behavioral and other risks in
current blood donors. DESIGN: Anonymous mail surveys to collect
demographic, medical, and behavioral information were administered to
individuals who had donated blood within the previous 2 months. Sampling
weights were used in the analysis to adjust for differential sampling and
response rates among demographic groups to provide prevalence estimates for
the donor population. SETTING: Five geographically and demographically
diverse US blood centers. PARTICIPANTS: A stratified probability sample of
50,162 allogeneic blood donors. MAIN OUTCOME MEASURES: Estimated prevalence
rates for risk behaviors that would have been a basis for deferral if
reported at the time of the donor screening interview (deferrable risk).
RESULTS: Completed questionnaires were received for 34,726 donors (69.2% of
the sample). A total of 186 per 10,000 respondents (1.9%) reported a
deferrable risk that was present at the time of their past donation, while
39 per 10,000 (0.4%) reported this behavior within the 3 months prior to
donation. Rates (with 95% confidence intervals [CIs]) of deferrable risk
behaviors were 1.4 (95% CI, 1.2-1.6) times higher for men than women, 1.6
(95% CI, 1.3-2.0) times higher for first-time vs repeat donors, 2.7 (95%
CI, 2.0-3.6) times higher for donors with reactive screening tests, and 7.6
(95% CI, 3.6-15.8) times higher for donors who used the confidential unit
exclusion option. CONCLUSIONS: Despite the high degree of transfusion
safety in the United States today, a measurable percentage of active blood
donors when assessed by anonymous survey report risks for human
immunodeficiency virus and other infections not reported at the time of
screening, suggesting the need for further refinements in the blood donor
qualification process.
