Development and validation of the Iranian version of the protection motivation theory questionnaire for fall prevention in older people

The protection motivation theory is a common framework illustrating the use of protective behaviours. The aim of this study was to develop and evaluate the psychometric properties of the protection motivation theory questionnaire for fall prevention in older people in Iran. This study used a psychometric design. A literature review was initially performed and developed a 35-item questionnaire consisting of eight sub-constructs of the protection motivation theory. A panel of experts and a group of older people aged 60 years or above were invited to assess the content and face validity of the questionnaire. Thereafter, construct validity was evaluated by using confirmatory factor analysis. The reliability of the questionnaire was examined using test–retest reliability and internal consistency. Data analysis was performed using the partial least squares path modelling version three software. A total of 300 people living in retirement centres completed the questionnaire. In the expert panel review, all tasks received a content validity index above 0.90 and a content validity ratio above 0.80, representing good content validity. In total, 32 items remained in the final version of the questionnaire. Confirmatory factor analysis confirmed an acceptable eight-factor model fit of the protection motivation theory sub-constructs with factor loadings from 0.59 to 0.93. The discriminant validity was verified using the Fornell–Larcker criterion. The Cronbach's alpha ranged from 0.68 to 0.90 and the test–retest reliability ranged from 0.78 to 0.90, displaying an acceptable result. The results of this study suggest that the protection motivation theory questionnaire had good validation and can be used to measure the psychological predictors of fall behaviour in older people. Further studies are needed to evaluate the validity in various settings.