Validity and Reliability of the Physical Disability Stigma Questionnaire

Stigma refers to negative and destructive attitudes and beliefs that society has towards some social groups, such as mental patients, disabled people, or a certain race. In Iran, there is no comprehensive and accurate questionnaire about the stigma of physical disability from a sociological point of view. Therefore, the purpose of this research was to determine the validity and reliability of the physical disability stigma questionnaire.

The present survey-cross-sectional study that was conducted among 620 people with physical disabilities living in Tehran and Yasuj cities using convenience sampling method. In order to evaluate the validity of the questionnaire, content, face, construct, convergent, discriminant, Cross-validated Communality and redundancy were used, and Cronbach's alpha, loop method, and composite reliability were used to evaluate reliability. Data were analyzed using SPSS ans PLS analytical softwares.

The results indicated that convergent validity was established at the level of variables (AVE > 0.50) and at the level of items (factor loadings > 0.40) which indicated the validity and accuracy of the investigated items to measure the related variables. According to factor loading values, in measuring social stigma, family stigma dimension (0.770); In the measurement of perceived stigma, the dimension of "feeling being seen differently (0.870)" and in the measurement of self-stigma, the dimension of "avoidance stigma (0.871)" had a greater impact than other dimensions. It was correspondingly displayed that divergent validity was established at the level of variables and items, and according to the Fornell-Larcker index, the square root of the extracted average variance of each factor was greater than the maximum correlation of that factor with other factors. The results of combined reliability indicated that the questionnaire had acceptable internal consistency reliability and the reliability of the measurement model was confirmed (CR > 0.70). Finally, the results of common cross-validity and redundancy revealed that the measurement model had good quality, appropriateness and predictive power (Q2 > 0.11).

According to the validity and reliability indicators of the measurement tool, it can be said that this questionnaire was appropriate in terms of content. The items were able to measure the desired variables. Moreover, the questionnaire had a worthy and satisfactory quality and can be a proper tool for measuring the physical disability stigma.