Criterion validity of the Pittsburgh Sleep Quality Index: Investigation in a non-clinical sample

Authors

  • Michael A GRANDNER,

    Corresponding author
    1. San Diego State University/University of California, San Diego Joint Doctoral Program in Clinical Psychology, San Diego,
    2. Circadian Pacemaker Laboratory, University of California, San Diego, Department of Psychiatry, La Jolla, California, USA;
      Mr Michael A. Grandner, UCSD Circadian Pacemaker Laboratory, 9500 Gilman Dr, Mail Code 0667, La Jolla, CA 92093-0667, USA. Email: MGrandner@UCSD.edu
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  • Daniel F KRIPKE,

    1. Circadian Pacemaker Laboratory, University of California, San Diego, Department of Psychiatry, La Jolla, California, USA;
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  • In-Young YOON,

    1. Department of Neuropsychiatry, Seoul National University Bundang Hospital, Gyeonggi-do, Korea; and
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  • Shawn D YOUNGSTEDT

    1. Department of Exercise Science, Arnold School of Public Health, University of South Carolina, Columbia, South Carolina, USA
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Mr Michael A. Grandner, UCSD Circadian Pacemaker Laboratory, 9500 Gilman Dr, Mail Code 0667, La Jolla, CA 92093-0667, USA. Email: MGrandner@UCSD.edu

Abstract

The objective of this study was to investigate the reliability and validity of the Pittsburgh Sleep Quality Index (PSQI) in a non-clinical sample consisting of younger and older adults. There has been little research validating the PSQI with respect to multinight recording as with actigraphy, and more validation is needed in samples not specifically selected for clinical disturbance. Also, the degree to which the PSQI scores may reflect depressive symptoms versus actual sleep disturbance remains unclear. One-hundred and twelve volunteers (53 younger and 59 older) were screened for their ability to perform treadmill exercises; inclusion was not based on sleep disturbance or depression. Internal homogeneity was evaluated by correlating PSQI component scores with the global score. Global and component scores were correlated with a sleep diary, actigraphy, and centers for epidemiological studies – depression scale scores to investigate criterion validity. Results showed high internal homogeneity. PSQI global score correlated appreciably with sleep diary variables and the depression scale, but not with any actigraphic sleep variables. These results suggest that the PSQI has good internal homogeneity, but may be less reflective of actual sleep parameters than a negative cognitive viewpoint or pessimistic thinking. The sleep complaints measured may often be more indicative of general dissatisfaction than of any specifically sleep-related disturbance.

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