The Design and Psychometric Properties of the Tendency to Use Covid-19 Vaccine Questionnaire based on the Health Belief Model

It is necessary to have a suitable tool for measuring the tendency to use the Covid-19 vaccine. The aim of this study was to determine the validity and reliability of the tendency to use Covid-19 vaccine questionnaire among health care workers of a hospital in Tehran, Iran. 

This is an instrumentation type of methodological. Fifty-six questions were considered as the items of the questionnaire. For testing the validity, the face validity and content validity were used in correspondence with 10 experts’ opinions. Reliability check was performed through the Cronbach's alpha and test- retest. Finally, the structural validity was evaluated with 474 subjects.

The results showed that the scales of the tendency to use Covid-19 vaccine questionnaire have an appropriate face validity for all items with an impact score higher than 1.5 and an appropriate content validity ratio in the range of 0.70 and a sufficient content validity index in the range of 0.73 to 087. Also, it had an acceptable internal consistency reliability (Cronbach's alpha) in the range of 0.87 to 0.96. Also, the reliability of the test-retest ranged from 0.68 to 0.92. For the structural validity, 8 factors were selected with a factor value higher than 0.4. Also, in the confirmatory section of the factors an acceptable goodness of fit index (GFI) (Range from 0.91 to 0.98) and the root mean square error in the range of 0.33 to 0.49 was achieved. In total, four questions were removed in the content validity ratio review stage and one question was removed in the content validity index review stage.

The results of this study showed that the tendency to use Covid-19 vaccine questionnaire has sufficient validity and reliability and is a suitable tool for evaluating the health staff’s tendency towards vaccination. Ultimately, this questionnaire was approved with 8 factors (perceived sensitivity, perceived severity, perceived benefits, perceived barriers, cues to action, ‌self-efficacy, knowledge and behavior) and 51 questions.