Primary sleep outcome measures
Pittsburgh Sleep Quality Index
The PSQI is a self-rated questionnaire that provides a measure of sleep disturbances over a 1-month time interval. Nineteen individual items generate 7 “component” scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction.24 The sum of scores for these 7 components yields 1 global score. Initially, Buysse and colleagues24 assessed clinical and psychometric properties of the PSQI over an 18-month period with “good” sleepers and “poor” sleepers. Acceptable measures of internal homogeneity, consistency (test-retest reliability), and validity were obtained. A global PSQI score greater than 5 yields a diagnostic sensitivity of 89.6% and specificity of 86.5% (P ≤ .001) in distinguishing between good and poor sleepers. The psychometric and clinical properties of the PSQI affirm its utility both in psychiatric clinical practice and in research activities.24 Patients completed a PSQI on 2nd and 28th day of treatment (if they were not discharged prior to the 28th day