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    Licensed instrument

    PSQI: scoring, cutoffs & interpretation

    Licensed 19-item index of past-month sleep quality. Information only - not available to score here.

    Use these instead

    ISIInsomnia Severity Index

    02 - The clinician's brief

    Last reviewed: · Reviewed by Lotte Kjær Svalberg

    01 - Scoring & cutoffs

    How scoring works.

    The PSQI contains 19 self-rated items covering the past month, combined into seven component scores - subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Each component is scored 0-3, and the components sum to a global score of 0-21, with higher scores indicating worse sleep quality. The validated cutoff is a global score greater than 5, which distinguished poor from good sleepers with sensitivity 89.6% and specificity 86.5% in the original validation study. There are no formally validated severity bands beyond this single cutoff, though higher scores indicate more severe difficulties.

    Score
    Severity
    Interpretation
    0–5
    Good sleep quality
    Below the clinical cutoff.
    6–21
    Poor sleep quality
    Above the validated >5 cutoff. Higher scores indicate greater severity, but bands within this range are not formally validated.

    02 - Validation evidence

    How well it performs.

    Internal consistency for the seven components is good (Cronbach's alpha 0.83), with test-retest reliability of r = 0.85 and sensitivity 89.6% and specificity 86.5% at the >5 cutoff in the original validation study (Buysse et al., 1989). The index has since been used in more than 1,500 studies and validated in over 35 populations (Mollayeva et al., 2016).

    α 0.83
    Internal consistency

    Across the seven component scores - Buysse et al. 1989

    r = 0.85
    Test-retest reliability

    Buysse et al. 1989

    89.6% / 86.5%
    Poor vs good sleepers

    Sensitivity / specificity at the >5 global-score cutoff - Buysse et al. 1989

    >1,500 studies
    Evidence base

    Validated in over 35 populations - Mollayeva et al. 2016

    03 - Licensing, explained

    How licensing works.

    The PSQI is copyrighted by the University of Pittsburgh. It may be reproduced without charge only for non-commercial research and educational purposes, and clinicians may use it in their own practice; any commercial use requires a licence from the University of Pittsburgh's Innovation Institute.

    Aisel therefore cannot host the questionnaire or a scorable version. Clinicians can obtain the instrument and scoring instructions from the University of Pittsburgh's Center for Sleep and Circadian Science.

    For a scorable insomnia measure in this library, see the ISI.

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