Predictors of HAV/HBV vaccination completion among methadone maintenance clients.

This randomized, controlled study (N = 256) was conducted to compare three interventions designed to promote hepatitis A virus (HAV) and hepatitis B virus (HBV) vaccination completion among clients undergoing methadone maintenance (MM) treatment. Participants were recruited from five MM treatment sites in Southern California and randomized into three groups: Motivational Interviewing-Single (MI-Single), Motivational Interviewing-Group (MI-Group); and Nurse-Led Hepatitis Health Promotion (HHP). All were offered the three-series HAV/HBV vaccine. A total of 148 participants completed the vaccine. Groups did not differ in rate of vaccination completion (73.6%, HHP group, vs. 65% and 69% for the MI-Single and MI-Group, respectively). The equivalence of findings across groups suggests the value of including nurses with a comprehensive health focus in promoting vaccination completion.