Objectives: To determine adolescents' completion rates and factors affecting completion time of hepatitis B (HBV) vaccination.
Methods: Prior to vaccination, participants from a hospital-based and school-based adolescent clinic completed questionnaires assessing sociodemographic variables, family/friend experience with HBV and the vaccine, likelihood of completing the vaccinations, HBV and vaccine knowledge, risk behaviors, chronic illness, and access to clinic. Vaccination times were recorded.
Results: Twenty-six months after initiation of the study, 72% of 896 eligible participants had completed the vaccination series. The independent predictors of shorter time to completion were: higher estimated mean household income [odds ratio (OR) = 1.15, 95% confidence interval (CI) = 1.06-1.25), white race (OR = 1.27, 95% CI = 1.01-1.58), female gender (OR = 1.58, 95% CI = 1.31-1.92], and not having smoked cigarettes (OR for smoking in the past 30 days = 0.74, 95% CI = 0.60-0.92). Site of care, risk factors for acquiring HBV, disease and vaccine knowledge, and self-reported desire to complete the series were not associated with completion time.
Conclusions: The primary factors associated with completion of immunization may not be amenable to intervention; mandated strategies for immunization may be more likely to result in protection for adolescents.