BACKGROUND A randomized controlled trial was conducted to test the effects of hydration and applied muscle tensing on presyncopal reactions to blood donation. Both interventions are designed to prevent the decreases in blood pressure that can contribute to such reactions, but due to the distinct physiological mechanisms underlying their pressor responses it was hypothesized that a combined intervention would yield the greatest benefit. STUDY DESIGN AND METHODS Prior to blood donation, first- and second-time blood donors (Mean Age = 20.2 years, SD = 4.9) were randomly assigned to: 1) standard donation, 2) placebo (leg exercise prior to venipuncture), 3) pre-donation water, or 4) pre-donation water and leg exercise during donation. RESULTS Main effects of group were observed for phlebotomist classification of vasovagal reactions, X2 (3) = 8.38, p<0.05, and donor reports of presyncopal reactions, X2 (3) = 13.16, p < 0.01. Follow-up analyses of phlebotomist classifications revealed fewer reactions in the pre-donation water and pre-donation water and leg exercise groups relative to placebo but not standard donation. Follow-up analyses of self-reported reactions revealed that women, but not men, had lower scores in both the pre-donation water and pre-donation water and leg exercise groups relative to both placebo and standard donation. CONCLUSION Pre-donation hydration and a combination of hydration and leg exercise may help attenuate presyncopal reactions in relatively novice donors, although future studies with larger samples are required to confirm this effect.

BACKGROUND Efforts to expand the donor pool by recruiting younger donors have resulted in higher numbers of initial donations, but retention of young donors continues to be a problem. STUDY DESIGN AND METHODS Path analysis was used to examine the simultaneous relationships among syncopal reactions, donation anxiety, needle pain, donor satisfaction, and donation intention in the prediction of repeat donation. Participants included 421 first- and second-time donors recruited for a study comparing the effects of pre-donation water loading with and without the use of applied muscle tension during donation (52% female, 60.8% first-time donor, mean age 20.3 years). For this longitudinal follow-up study, donor database records were accessed two years after the index donation to determine whether a repeat donation had been attempted. RESULTS Results of a series of path analyses demonstrated the influential role of donor anxiety in shaping donor retention (final model Χ2=35.75, RMSEA=0.03, CFI=0.98, WRMR=0.74). First, anxiety exerted a direct negative influence on donation intention, the proximal and sole direct predictor of repeat donation. Second, anxiety increased the likelihood of donor-reported needle pain, adversely affecting donation satisfaction and, subsequently, donation intention. Finally, anxiety was associated with donor ratings of syncopal reactions through its impact on needle pain, which also contributed to decreased donation intention. CONCLUSION These results provide novel evidence that donation anxiety plays a central role in shaping future donation behavior; hence, individual differences in anxiety must be considered when developing and testing strategies to enhance blood donor retention.