Validation and Cultural Adaptation of the Motors of COVID-19 Vaccination Acceptance Scale (MoVac-COVID19S) in German

Abstract

Abstract: Background: Context-specific standardized psychometric instruments are essential for ensuring valid and reliable assessment of health outcomes across diverse populations to aid the advancement of research and health-related interventions. However, instruments measuring attitudes toward vaccinations are lacking in the extant literature. Therefore, we performed a cross-cultural adaptation of the Motors of COVID-19 Vaccination Acceptance Scale (MoVac-COVID19S) in Germany. Method: During the months of June and July 2022, 475 individuals aged 18 years and older from the general population of Germany participated in an online cross-sectional survey. Participants responded to five demographic questions, a measure of COVID-19 vaccine uptake willingness, and the MoVac-COVID19S. Confirmatory Factor Analysis (CFA) fit indices were used to evaluate the factor structures of the MoVac-COVID19S. Results: The CFA revealed that all examined factor structures of both the 9-item and 12-item versions of the MoVac-COVID19S were acceptable among the sample. Overall, CFI, GFI, and TLI values were higher than 0.95; RMSEA and SRMR values were all less than 0.08 for all the estimated models. The one-factor model of the 9-item version of the MoVac-COVID19S exhibited best fits indices compared to the one-factor and four-factor structures of the 12-item version of the scale. The bifactor model revealed that the general factor explained a higher percentage of the Explained Common Variance (ECV; ranging from 55% to 94%) in the majority of the items, compared to the specific factors. The scale was found to demonstrate convergent validity with related measures. Conclusion: The German version of the MoVac-COVID19S should be considered a unidimensional rather than a multidimensional measure. Although the 9-item version of the scale performed better among the sample compared to the 12-item version, the overall scores of both versions were found to be valid and reliable measures of attitudes toward COVID-19 vaccinations. The MoVac-COVID19S has the potential to be adapted for assessing attitudes toward any future vaccination programs. Limitations: While our study sampled only the general German population, the criticisms of CFA warrant further research using advanced methods, such as the Rasch model, and subgroups.