Can self-prediction overcome barriers to Hepatitis B vaccination? A randomized controlled trial.

OBJECTIVE Hepatitis B virus (HBV) infection remains a serious public health problem, due in part to low vaccination rates among high-risk adults, many of whom decline vaccination because of barriers such as perceived inconvenience or discomfort. This study evaluates the efficacy of a self-prediction intervention to increase HBV vaccination rates among high-risk adults. METHOD Randomized controlled trial of 1,175 adults recruited from three sexually transmitted disease clinics in the United States over 28 months. Participants completed an audio-computer-assisted self-interview, which presented information about HBV infection and vaccination, and measured relevant beliefs, behaviors, and demographics. Half of participants were assigned randomly to a "self-prediction" intervention, asking them to predict their future acceptance of HBV vaccination. The main outcome measure was subsequent vaccination behavior. Other measures included perceived barriers to HBV vaccination, measured prior to the intervention. RESULTS There was a significant interaction between the intervention and vaccination barriers, indicating the effect of the intervention differed depending on perceived vaccination barriers. Among high-barriers patients, the intervention significantly increased vaccination acceptance. Among low-barriers patients, the intervention did not influence vaccination acceptance. CONCLUSIONS The self-prediction intervention significantly increased vaccination acceptance among "high-barriers" patients, who typically have very low vaccination rates. This brief intervention could be a useful tool in increasing vaccine uptake among high-barriers patients.