Scoring and psychometric validation of the ‘Determinants of Intentions to Vaccinate’ (DIVA©) questionnaire

BACKGROUND Primary care physicians (PCPs) play a key role regarding vaccination in France. The aims of the present study were to define the scoring rules and to assess the measurement properties of the 'Determinants of Intentions to Vaccinate' (DIVA©) questionnaire that aims to assess PCPs' attitudes and beliefs toward vaccination. METHODS The DIVA questionnaire was derived from a literature review and PCPs focus groups. Scoring and early validation of the DIVA questionnaire were determined during a cross-sectional study conducted in France. During the study, PCPs had to complete the DIVA questionnaire for any of the six vaccine-preventable diseases (VPDs) to which they were randomly assigned (measles, pertussis, pneumococcus infection, seasonal influenza, human papillomavirus -HPV- infection and tetanus). Descriptive analyses of items and the analysis of the grouping of items into domains were conducted. Internal consistency reliability and construct validity was assessed according to each VPD. RESULTS The DIVA questionnaire was completed by 1,069 PCPs and was well accepted. The 'Commitment of the PCP to the vaccination approach' score showed very good internal consistency reliability (Cronbach's alpha >0.70 overall and for each VPD). The construct validity of the DIVA questionnaire was confirmed. CONCLUSIONS The DIVA questionnaire is a valid and reliable measure of PCPs' attitudes and beliefs toward vaccination.