BACKGROUND: Predonation screening has become more elaborate over the years, while human immunodeficiency virus (HIV)- and hepatitis C virus (HCV)-positive donations have declined. The impact of face-to-face interviewing and of the format of the Donor Health Assessment Questionnaire (DHAQ) have not been evaluated.

STUDY DESIGN AND METHODS: Canadian Blood Services DHAQ records between 1990 and 2004 were examined, and changes in them were tracked. The proportion of first-time donors permanently deferred for HIV or HCV risk, and the HIV and HCV rates per 100,000 donations, were calculated annually. Time-series analysis was used to determine whether major predonation screening changes had any effect on the HIV or HCV rates or permanent deferrals.

RESULTS: In 1992, receiving money or drugs for sex was added to the DHAQ; otherwise, the content of high-risk questions changed little between 1990 and 2004. In 1997, the method of administration of the DHAQ changed from donor-completed to face-to-face interviewing for high-risk questions. Permanent deferrals for HIV or HCV risk factors and HIV and HCV rates in first-time donors decreased over this period. The HIV rates were close to 0 before 1997, whereas HCV rates decreased steadily through 2004. There was no interruption in rates in 1997 when the method of administration changed.

CONCLUSION: Face-to-face interviewing for high-risk questions had no effect on HIV or HCV rates in first-time donations over 15 years of observation (during the latter 8 of which face-to-face interviewing was in place), and it did not increase permanent deferrals for HIV or HCV risk factors.