BACKGROUND: The validity of studies relying on self-report of blood donation may be severely threatened by systematic errors.
STUDY DESIGN AND METHODS: We linked the Sax Institute's 45 and Up Study data, which asked self-report of blood and plasma donation including the date of most recent donation to the blood donor database at the Australian Red Cross Blood Service. We used the linked data to validate the accuracy of self-reported blood donation history including the completeness and accuracy of reported date of most recent donation.
RESULTS: Of the total 142,503 participants, 47.8 and 5.1% reported ever donating blood and plasma, respectively. Of those self-reporting blood donation (n = 23,113) and plasma donation (n = 4,451) within the last 10 years of survey, 6262 (27.1%) and 1444 (33.0%) had no record of donation within that period, respectively. Among those who had a record of blood and plasma donation within 10 years before the survey, 97.6 and 93.0% correctly self-reported ever donating blood and plasma, respectively. Donors consistently reported a donation date more recent than the actual recorded date, and the median discrepancy and variability increased as the length of time from the survey date to the actual date of donation increased.
CONCLUSIONS: Almost 98% of donors donating blood within a decade of survey completion date can correctly self-report their history of donation as ever donating blood, whereas 27% of participants self-reporting donation within a decade may not have actually donated blood. Further, self-reported date of blood donation is not a reliable measure of actual date of donation.