Purpose: Middle school entry laws increase coverage with recommended vaccines, but their effect on vaccines that are not required is unknown. We compared vaccination coverage for hepatitis B, tetanus and diphtheria (Td), and measles, mumps and rubella (MMR) in areas of states with discordant middle school, hepatitis B school entry laws, and evaluated the relationship between demographic characteristics and adolescent immunization rates.
Methods: Retrospective design with purposive school sampling, using location of residence to determine study group. In each school, immunization records from a random sample of up to 75 students in ninth grade (affected by a new hepatitis B law) and 12th grade (not affected by the law) from 11 schools in two areas discordant for the law were analyzed. All areas had long standing two-dose MMR and Td requirements.
Results: Ninth graders in schools with the law had hepatitis B rates higher (72.8%) than those without the law (18.6%) (U = 2.0, p < .01). There were no significant differences between grades or schools for MMR and Td. However, even in the presence of the law, rates were significantly lower in schools with lower socioeconomic indicators.
Conclusions: Middle school immunization laws are effective at raising adolescent hepatitis B, but in this study there wasn't enough power to discern the effect on rates for other vaccines or the influence of demographic variables on rates. Results suggested that laws did not appear to completely overcome disparities. For school mandates to be more effective, additional efforts, presumably on enforcement, especially in areas with lower socioeconomic indicators, are needed.