Pre-donation screening for blood safety: comparison between 3-and 6-month deferral of men who have sex with men and the incorporation of individual risk assessment

Abstract

Introduction: Advances in blood donor screening have supported the shortening of deferral intervals and incorporation of individual risk assessment. This study investigated the potential impacts of comparing 3- and 6-month deferral periods for men who have sex with men and introducing a behaviour-based individual risk assessment policy in Hong Kong, particularly on donor eligibility and blood safety. Methods: A cross-sectional study was conducted in March 2024, recruiting individuals who had successfully donated blood in October 2023 in Hong Kong. Participants completed a survey on transfusion-transmissible infection risk–related deferrable behaviours, as described in the pre-donation screening questionnaire, and the United States Food and Drug Administration–proposed individual risk assessment items within 6 months before donation. Bivariable and multivariable (backward) logistic regression analyses were performed to identify factors associated with non-compliance. Presumptive non-compliance rates were calculated based on the timing of the most recent reported risk behaviour. Results: Of 2268 responses received, 1720 (median age=46 years; 50.8% male) were analysed. The non-compliance rate under the prevailing 6-month deferral policy was 4.01% (95% confidence interval [95% CI]=3.16%-5.02%). Non-compliant donors were more likely to be male (adjusted odds ratio [aOR]=2.049, 95% CI=1.216-3.451) and to perceive themselves as healthy (aOR=1.248, 95% CI=1.024-1.521), but less likely to believe in personal responsibility for blood safety (aOR=0.846, 95% CI=0.766-0.935). Presumptive non-compliance rates were 2.79% for 3-month deferral under the prevailing policy and 2.27% for 3-month deferral incorporating individual risk assessment. Of the five individuals who would have been deferred for male-to-male sexual activities under the prevailing policy with a 3-month deferral period, two would have become eligible under individual risk assessment. Conclusions: Shortening deferral intervals had modest effects on donor compliance. Incorporating individual risk assessment could improve identification of potential donors with higher-risk sexual behaviours while moderately expanding the donor pool.