The Vaccination Confidence Scale: a brief measure of parents' vaccination beliefs

Purpose: The success of national immunization programs depends on the public's confidence in vaccines. We sought to develop a scale for measuring confidence about adolescent vaccination in diverse populations of parents.

Methods: Data came from 9623 parents who completed the 2010 National Immunization Survey-Teen, an annual, population-based telephone survey. Parents reported on a 13- to 17-year-old child in their households. We used exploratory and confirmatory factor analysis to identify latent constructs underlying parents' responses to 8 vaccination belief survey items (response scale 0-10) conceptualized using the Health Belief Model. We assessed the scale's psychometric properties overall and across demographic subgroups.

Results: Parents' confidence about adolescent vaccination was generally high. Analyses provided support for three factors assessing benefits of vaccination (mean=8.5), harms of vaccination (mean=3.3), and trust in healthcare providers (mean=9.0). The model showed good fit both overall (comparative fit index=0.97) and across demographic subgroups, although internal consistency was variable for the three factors. We found lower confidence among several potentially vulnerable subpopulations, including mothers with lower levels of education and parents whose children were of Hispanic ethnicity (both p<0.05).

Conclusions: Our brief, three-factor scale offers an efficient way to measure confidence in adolescent vaccination across demographic subgroups. Given evidence of lower confidence by educational attainment and race/ethnicity, program planners should consider factors such as health literacy and cultural competence when designing interventions to promote adolescent vaccination to ensure these programs are fully accessible.