Psychometric Characteristics of the Pittsburgh Sleep Quality Index in English Speaking Non-Hispanic Whites and English and Spanish Speaking Hispanics of Mexican Descent

Study Objectives: The current study investigated the factor structure of the Pittsburgh Sleep Quality Index (PSQI) among English speaking non-Hispanic whites (NHW) and English and Spanish speaking Hispanics of Mexican descent (HMD). Design: The PSQI was administered during a telephone interview. In order to test the factor structure of the PSQI structure across ethnic/language groups, multiple group confirmatory analysis with covariates (MIMIC) was employed. The 1- and 3-factor versions of the PSQI previously reported in the literature were examined. Setting: San Diego County. Participants: Community-dwelling English speaking, NHW (n = 1,698) and English (n = 654) and Spanish (n = 792) speaking HMD. Measurement and Results: A single-factor scoring model fit across language/ethnic groups; however, a 3-factor model provided a better than the 1-factor model in all language/ethnic groups. The subscale "sleep medications" loaded poorly and was removed from all models. Conclusion: Across groups, a 3-factor model of the PSQI more reliably assessed sleep quality than a single-factor global score. Results indicate that the 3-factor structure of the PSQI was uniform across English speaking NHW and English and Spanish speaking HMD.