Application of Rasch model for evaluating the quality of life in blind war veterans

Background: Quality of life evaluates the general well-being of individuals and it can be considered as one of the important aspects in programming and giving service to disabled people. Blindness is one of the most important kinds of physical disability that has a direct effect on quality of life, so this study aimed to explore how war blindness influences the quality of life. Methods: In this cross-sectional study, data from 71 blind war (Iran-Iraq) veterans in 2010 were collected using the Short Form Health Survey instrument (SF36). Rasch model was fitted by running WINSTEPS software and then item parameter (B), i.e. difficulty of items, and person parameter (?), i.e. the ability or attainment level of respondents, were estimated. Results: In a total of 71 cases, 69 cases (97 %) were male with a mean (±SD) age and blindness duration range of 48.97 (±10.655) yrs and 25.74 (±3.692) yrs, respectively. Item difficulty ranged from 2.962 to 4.441. Comparison of the SF36 scores and Rasch measurements showed that standard error of Rasch model estimates in physical and total scores are less than SF36 scores. Conclusion: Due to the advantages and higher accuracy of the Rasch model, using this model can be a good alternative for the traditional models. With due regard to the relative low quality of life of blind war veterans in this study and other similar study, further investigation are recommended to be carried out to this group of society.