Development and validation of a short instrument for measuring attitude towards Covid-19 vaccination: The covid-19 vaccination attitude scale for adults (Co-VASA)

Acceptance of COVID-19 vaccination could be influenced by attitude towards the vaccine. The aim of this study was to develop and evaluate the validity and reliability of adult attitudes towards COVID-19 vaccination.

First, an item pool was generated by reviewing existing resources. Then content and face validity was examined. In the next stage, the structural validity (exploratory and confirmatory factor analysis) of the questionnaire was examined in two distinct samples among 505 Iranian adults. Finally, the attitude was assessed among two samples. The internal consistency of the instrument was estimated by calculating Cronbach's alpha.

The initial questionnaire consisted of 38 items that after examining the content and face validity, a number of items was removed and corrections were applied to the remaining items. The results of exploratory factor analysis showed a three factor solution (emphasis on the need for corona vaccine, no need for corona vaccine and emphasis on the side effects of corona vaccine) including 13 items that jointly explained about 52% of variance observed. Similarly, the results obtained from confirmatory factor analysis indicate a good fit for the data. The fit indexes were as follows: (X2/df =2.15, GFI=0.91, CFI=0.95, NFI=0.91, NNFI=0.94, SRMR=0.068, RMSEA=0.076). The reliability of the questionnaire as assessed by the Cronbach’s alpha was 0.853 for the scale and ranged from 0.68-0.74 for its dimensions. Finally, the mean attitude score of the participants was 64.1 out of 100 points.

Considering the validity and reliability of the attitude assessment questionnaire regarding the COVID-19 vaccination in adults, this questionnaire could be used for measuring attitude towards COVID-19 vaccination.