Drug users' participation in a free hepatitis B vaccination program: demographic, behavioral, and social-cognitive determinants.

The present study was conducted as an evaluation of a two-year pilot program started in 1998 in the Netherlands to provide free hepatitis B vaccination targeted at drug users (DUs). In order to identify which demographic and social-cognitive factors predict vaccination uptake, written questionnaires were distributed in three pilot regions (Amsterdam, Tiel, and Maastricht) amongst all DUs that were invited to participate in the program during a 2-month period. Vaccination behavior 2 years later was anonymously and prospectively linked to the questionnaire data, which allowed us to investigate which factors predict vaccination behavior. Of the 207 DUs eligible for vaccination (i.e., who were not immune and/or had no current infection with the virus), 93 DUs had obtained vaccination in the 2 years following the questionnaire. More than half of them (N = 50) had completed the full program (3 injections). As possible predictors of vaccination uptake, the questionnaire included constructs of the Theory of Planned Behavior as well as of the Health Belief Model. Our results show that attitude toward obtaining hepatitis B vaccination was positively associated with intention toward obtaining hepatitis B vaccination. However, perceived behavioral control was found to be the only construct related to actual vaccination uptake. None of the demographic variables were related to vaccination uptake. Our findings suggest that future interventions aimed at increasing uptake of vaccination against hepatitis B in DUs should address DUs (perceived) control concerning this behavior. The study's limitations are noted.

Social-cognitive determinants of vaccination behavior against hepatitis B: an assessment among men who have sex with men.

BACKGROUND: Many individuals who are at risk for infection with the hepatitis B virus (HBV), including men who have sex with men (MSM), are not vaccinated. This study assessed social-cognitive determinants of obtaining vaccination against HBV. METHODS: A targeted survey was conducted among 432 MSM by means of a written questionnaire that contained assessments of social-cognitive determinants of vaccination behavior derived from the Health Belief Model (HBM) and the Theory of Planned Behavior. Vaccination behavior was anonymously linked to questionnaire data for which informed consent was obtained. RESULTS: Of the 290 men eligible for vaccination, 248 (86%) had obtained vaccination. Multivariate logistic regression analysis showed that these men were younger, more often were in a steady relationship, and had fewer sex partners. In addition, significant effects were also found for central factors proposed by the Health Belief Model. Notably, men who obtained vaccination against HBV perceived more personal threat from HBV. None of the Theory of Planned Behavior variables were related to obtaining vaccination. CONCLUSIONS: Findings suggest that health education interventions that address perceived susceptibility and severity are likely to contribute to increased uptake of HBV vaccination among MSM. Influencing perceived susceptibility in particular is important, more so than increasing perceived severity by scare tactics.