Claim: The Pittsburgh Sleep Quality Index is a questionnaire, developed by University of Pittsburgh researchers, that is designed to assess seven components of a subject's sleep quality.
Evidence: The Pittsburgh Sleep Quality Index (PSQI) is a self-report questionnaire that assesses sleep quality over a 1-month time interval. Developed by researchers at the University of Pittsburgh, the PSQI is intended to be a standardized sleep questionnaire for clinicians and researchers to use with ease and is used for multiple populations. The measure consists of 19 individual items, creating 7 components that produce one global score, and takes 5–10 minutes to complete.