ABSTRACT
Close to 20 years after the initial validation paper introducing the PSQI, the index has become one of the most widely used and well-validated instruments to measure sleep quality, translated into over 20 different languages, and cited in over 300 peer-reviewed articles. Herein, we describe the instrument and its development, summarize the psychometric properties based on the original Pittsburgh validation sample and as conducted by several other independent laboratories, and discuss common issues and avenues for future research.
The PSQI consists of 19 self-rated questions and five questions rated by the bed partner or roommate. The initial selection of items was derived from three sources: (1) expert knowledge of common complaints reported by sleep-disordered patients; (2) review of sleep quality questionnaires in the extant literature; and (3) clinical experience with the items during 18 months of pilot testing. The five questions addressing the bed partner were developed for clinical purposes only and are not included in the scoring of the PSQI; nor are there any validation data available on these items. However, these items may represent an important opportunity for the next generation of sleep research.
