PSYCHOMETRIC EVALUATION OF THE PITTSBURGH SLEEP QUALITY INDEX

The Pittsburgh Sleep Quality Index (PSQI) measures sleep quality and d isturbance retrospectively over a 1-month period using self-reports. A lthough the PSQI has been used in a variety of populations, published psychometric data are limited. The goal of this study was to examine p sychometric properties of the PSQI among four populations: bone marrow transplant patients (n = 155); renal transplant patients (n = 56); wo men with breast cancer (n = 102); and women with benign breast problem s (n = 159). Results supported PSQI internal consistency reliability a nd construct validity. Cronbach's alphas were 0.80 across groups and c orrelations between global and component scores were moderate to high. PSQI scores were moderately to highly correlated with measures of sle ep quality and sleep problems, and poorly correlated with unrelated co nstructs. Individuals with sleep problems. poor sleep quality, and sle ep restlessness had significantly higher PSQI scores in comparison to individuals without such problems. (C) 1998 Elsevier Science Inc.