Validity and reliability of the Persian version of the Athens Insomnia Scale
Reihaneh Heidari, Arezu Najafi, Farzaneh Jahanbakhsh, Reza Erfanian, Mostafa Yazdani
Background: Insomnia is a common disorder worldwide, and is an important issue in Iranian population. The Athens Insomnia Scale is a brief questionnaire that can be used as an effective diagnostic tool. We evaluated the validity and reliability of the Athens Insomnia Scale among a population of Iranian patients. The standard forward-backward method was utilized for translating the Athens Insomnia Scale from English to Persian. Coronbach’s alpha was used for calculation of internal consistency and inters correlations between the Athens Insomnia Scale subscales were calculated as well. From a subsample (n = 21) test– retest reliability was calculated. Analysis of face, content and convergent validity were conducted. Factor analysis was also performed and finally construct validity was assessed. Results: Cronbach’s alpha was 0.86. The test–retest reliability was excellent (0.98). Face and content validity were confirmed. Significant correlations of the Athens Insomnia Scale with the Pittsburgh Sleep Quality Index and Insomnia severity index confirmed convergent validity. Factor analysis revealed that this scale had two factors; one known as nighttime symptoms, and another known as daytime symptoms. The reliability of the instrument was confirmed by two methods of calculating Cronbach’s alpha and the test-retest method. The face and content validity was confirmed by the experts’ opinion method and by calculating the content validity ratio and content validity index. Convergent validity with a strong correlation between the Athens scale score and two other standard instruments were confirmed and construct validity was confirmed using exploratory factor analysis and correlation coefficient calculation. This study did not include special populations such as children or the elderly, and it is recommended to investigate validity in these populations in future studies.