Psychometric properties of family quality of life questionnaire (FQOL) based on Item-Response Theory (IRT)

The purpose of this research was to study the psychometric properties of family quality of life questionnaire based on. This study is a survey with a sample of 384 students (175 boys and 209 girls) were selected multistage cluster sampling among students of Azad University Central Tehran Branch. In this research, the family quality of life questionnaire was first translated into Farsi and then carried out for a total of 50Bachelor students. Among 25 items in the questionnaire, 4 Items (25-23-24), which conditioned by disabled family member, was not answered; therefore, the analysis process was eliminated and the rest of the analysis was done with 21 remaining Items. The results of the first order confirmatory factor analysis showed that all indices were significant at 99% level, indicating that the items are consistent with the theoretical construct. Its Cronbach's alpha coefficient was satisfactory for the whole scale and its components. The results showed that the reliability of the test was calculated using Cronbach's alpha for the total questionnaire of 0.779 and the components of family interactions 0.712, parenting 0.809, emotional well-being of 0.734 and physical well-being of 0. 804 and the desirability of the psychometric properties of the item questionnaire with the use of the GRM model were investigated. This study confirmed that family quality of life questionnaire can be used as a valid and appropriate tool for assessing the quality of life in the family in Iranian students. The validity is proposed of this questionnaire at the general population.