The Internal Consistency and Validity of the Vaccination Attitudes Examination Scale: A Replication Study.

BACKGROUND: Vaccinations are important preventative health behaviors. The recently developed Vaccination Attitudes Examination (VAX) Scale aims to measure the reasons behind refusal/hesitancy regarding vaccinations. PURPOSE: The aim of this replication study is to conduct an independent test of the newly developed VAX Scale in the UK. We tested (a) internal consistency (Cronbach's α); (b) convergent validity by assessing its relationships with beliefs about medication, medical mistrust, and perceived sensitivity to medicines; and (c) construct validity by testing how well the VAX Scale discriminated between vaccinators and nonvaccinators. METHODS: A sample of 243 UK adults completed the VAX Scale, the Beliefs About Medicines Questionnaire, the Perceived Sensitivity to Medicines Scale, and the Medical Mistrust Index, in addition to demographics of age, gender, education levels, and social deprivation. Participants were asked (a) whether they received an influenza vaccination in the past year and (b) if they had a young child, whether they had vaccinated the young child against influenza in the past year. RESULTS: The VAX (a) demonstrated high internal consistency (α = .92); (b) was positively correlated with medical mistrust and beliefs about medicines, and less strongly correlated with perceived sensitivity to medicines; and (c) successfully differentiated parental influenza vaccinators from nonvaccinators. CONCLUSION: The VAX demonstrated good internal consistency, convergent validity, and construct validity in an independent UK sample. It appears to be a useful measure to help us understand the health beliefs that promote or deter vaccination behavior.