The measure consists of 19 individual items, creating 7 components that produce one global score, and takes 5–10 minutes to complete.
The questionnaire has been used in many settings, including research and clinical activities, and has been used in the diagnosis of sleep disorders.
[3] The PSQI was developed in 1989, by Buysse and his colleagues, to create a standardized measure designed to gather consistent information about the subjective nature of people's sleep habits and provide a clear index that both clinicians and patients can use.
Traditionally, the items from the PSQI have been summed to create a total score to measure overall sleep quality.
[12] The PSQI has the same problems as other self-report inventories in that scores can be easily exaggerated or minimized by the person completing them.