Development and validation of a multi-dimensional COVID-19 vaccine hesitancy questionnaire

Since the emergence of the COVID-19 pandemic, vaccines have been developed to tackle the disease. However, many people worldwide were not confident enough to take the vaccines. Developing a questionnaire to measure COVID-19 vaccine hesitancy will give the health authorities and policymakers a clear picture to establish appropriate interventions addressing vaccine hesitancy among the community.

In this study, we used a mixed-method design over two phases. Phase 1 entailed a qualitative approach to developing the questionnaire, including a literature search, expert panel review, and focus group discussion. Phase 2 used a quantitative method for establishing the content and construct validity of the questionnaire via exploratory and confirmatory factor analysis (EFA & CFA). Internal consistency was checked using Cronbach's Alpha and intraclass correlation coefficient.

We developed a 50-item instrument designed to measure COVID-19 vaccine hesitancy among adults in the state of Qatar. The study involved 545 adult participants. In terms of content validity, our study showed a value of 0.92 for the scale-level content validity index based on the average and a value of 0.76 for the scale-level content validity index - universal agreement. In the EFA, the Kaiser-Meyer-Olkin measure of sampling adequacy was calculated at 0.78, with statistical significance (P = 0.001). Regarding model fit indices of the seven-factor model, our findings showed an acceptable model-data-fit, with a relative chi-square: 1.7 (<3), Root mean square error of approximation: 0.05 (<0.08), PCLOSE = 0.41, Comparative fit index: 0.909, Tucker-Lewis index: 0.902, Incremental Fit Index: 0.910 and, Standardized Root mean square residual: 0.067 (<0.08). The seven-factor model of the questionnaire met the criterion of good internal consistency (Cronbach's alpha = 0.73).

This tool is deemed of methodological merits in terms of validity, reliability, and determining the underlying conceptual structure of COVID-19 vaccine hesitancy and its associating factors.