<p class="first" id="d14989952e77">Despite the prevalence of sleep complaints among
psychiatric patients, few questionnaires
have been specifically designed to measure sleep quality in clinical populations.
The Pittsburgh Sleep Quality Index (PSQI) is a self-rated questionnaire which assesses
sleep quality and disturbances over a 1-month time interval. Nineteen individual items
generate seven "component" scores: subjective sleep quality, sleep latency, sleep
duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication,
and daytime dysfunction. The sum of scores for these seven components yields one global
score. Clinical and clinimetric properties of the PSQI were assessed over an 18-month
period with "good" sleepers (healthy subjects, n = 52) and "poor" sleepers (depressed
patients, n = 54; sleep-disorder patients, n = 62). Acceptable measures of internal
homogeneity, consistency (test-retest reliability), and validity were obtained. A
global PSQI score greater than 5 yielded a diagnostic sensitivity of 89.6% and specificity
of 86.5% (kappa = 0.75, p less than 0.001) in distinguishing good and poor sleepers.
The clinimetric and clinical properties of the PSQI suggest its utility both in psychiatric
clinical practice and research activities.