Psychometric Properties of the Persian Translation of Pittsburgh Sleep Quality Index

Abstract

Background: Pittsburgh sleep quality index (PSQI) is one of the most important instruments frequently used to assess sleep quality. This questionnaire is used to assess sleep styles and quality in adults through seven dimensions. Objectives: The study aims to investigate the reliability, validity and factor structure of the Persian version of PSQI. Materials and Methods: A Survey method with quantitative analytic approach was used in this research. A sample of 415 employees of Kerman hospitals participated in this study and filled the questionnaire. Forward-backward method was applied to translate the questionnaire from English to Persian. The following aspects of the Persian version of PSQI were evaluated: internal consistency (using Chronbach’s alpha), concurrent validity (correlation with GHQ-28), and factor structure of the questionnaire. Results: Mean age of the participants was 35.18 years, and participants’ average year of education was 15.3. The Chronbach’s alpha coefficient was 0.55. According to the factor analysis, three factors were extracted accounting for 63.485% of the total variance. There was a significant correlation among different dimensions of the Persian version of PSQI. Concurrent validity analysis showed that PSQI and GHQ-28 were correlated significantly. Conclusions: The Persian version of PSQI exerted a satisfactory validity and reliability in our sample.