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The Pittsburgh Sleep Quality Index (PSQI)

Interested in using the PSQI? Request PSQI

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PSQI Instrument

PSQI Article

PSQI Scoring Guidelines

What is the PSQI?

 The Pittsburgh Sleep Quality Index (PSQI) is a widely used self-report questionnaire that assesses sleep quality over a one-month time interval. The measure was developed by Dr. Daniel Buysse, Dr. Charles Reynolds, Dr. Timothy Monk, Dr. Susan Berman, and Dr. David Kupfer at the University of Pittsburgh. Since the PSQI’s publication in 1989, it has been cited in over 34,000 peer-reviewed articles.

The PSQI is commonly used in both clinical and research settings to evaluate various aspects of sleep. It is a valuable tool for assessing sleep quality as it captures multiple dimensions of sleep, including both subjective experiences and objective parameters. It allows researchers and healthcare providers alike to obtain a comprehensive understanding of an individual’s sleep patterns and disturbances and inform treatment decisions and interventions for sleep disorders.

Three of the PSQI's developers (left to right): Dr. Kupfer, Dr. Reynolds, and Dr. Buysse
Three of the PSQI's developers (left to right): Dr. Kupfer, Dr. Reynolds, and Dr. Buysse
Validity of the PSQI

The validity of the Pittsburgh Sleep Quality Index (PSQI) was rigorously examined. Significant differences were observed in global PSQI scores between subject groups, with control subjects differing from patient groups. Further analysis demonstrated distinct profiles for different patient groups, reinforcing the PSQI’s ability to discriminate between varying levels of sleep disturbances. Covariate analysis confirmed the robustness of these findings, with age and sex having minimal impact on group differences.

Additionally, the PSQI’s validity was supported by its consistent performance in identifying individuals with sleep disturbances using a post hoc cutoff score. Comparative analysis with polysomnography further substantiated the PSQI’s validity, showing alignment with objective measures of sleep quality across various subject groups.

Overall, these findings underscore the PSQI’s reliability and utility in assessing sleep quality across diverse populations and contexts. More information on PSQI’s validity can be found in the original article.   

Using the PSQI

Please cite the reference for the PSQI in any publications:

Buysse,D.J., Reynolds,C.F., Monk,T.H., Berman,S.R., & Kupfer,D.J. (1989). The Pittsburgh Sleep Quality Index (PSQI): A new instrument for psychiatric research and practice. Psychiatry Research, 28(2), 193-213. 

If you intend to reproduce or reprint the original PSQI article, please fill out the request form.

The PSQI instrument is owned by the University of Pittsburgh and may be reprinted without charge only for non-commercial research and educational purposes. You may not make changes or modifications of this form without prior written permission from the University of Pittsburgh. If you would like to use this instrument for commercial purposes or for commercially sponsored research, please fill out the request form.

The PSQI has been translated into 56 additional languages. For more information on these languages, or to request the PSQI in a different language, follow the link to the MAPI website. You will have to create a profile (free) and then click on PSQI Request for Translations under Conditions of Use heading.

Not sure where to start? Fill out the request form!

Scoring the PSQI

Each component score of the PSQI ranges from 0 to 3, with 3 indicating the greatest dysfunction or disturbance. The seven component scores are then summed to obtain a global PSQI score, which ranges from 0 to 21. Higher scores indicate poorer sleep quality, with a score greater than 5 suggesting significant sleep difficulties.

 

Please see PSQI Scoring for more information.

PSQI Use Pricing

Research

 

 

 

Use of PSQI in non-commercial study (academic or US government funded)

FREE

  Use of PSQI in a commercial study funded by a for profit entity with 50 or fewer employees AND comprising 100 or fewer participants $5,000 per Study

 

Use of PSQI in commercial study funded by a for profit entity, that does not meet either of the above conditions

$20,000 per Study

Publication

 

 

 

Link to the English version of PSQI in an academic publication

FREE

 

Include the full PSQI in an academic publication

$5,000

 

Include the full PSQI in a commercial publication

Per use fee*

Educational Program

Link to the PSQI in an educational program

FREE

 

Include the full PSQI in an academic educational program

$5,000

 

Include the full PSQI in a commercial educational program

Per use fee*

Clinical Use

Use of the PSQI for clinical/ patient use

Per use fee*

Other Uses

Use of the PSQI for internal commercial use

Per use fee*

 

Distribution of the PSQI or data generated from the use of the PSQI to customers/ clients

Varies/ Please contact

*Per Use Fee Structure (Annual)

<250 uses

$1,000
251 – 500 uses $2,500

501-1,000 uses

$5,000

1,001 – 2,500 uses

$9,000

2,501 – 5,000 uses

$12,000

5,001 – 10,000 uses

$15,000

> 10,000 uses

$20,000

Validation Articles

 

The PSQI: Validity and factor structure in young people

Criterion validity of the PSQI: Investigation in a non-clinical sample

Validation of a 3-factor scoring model for the PSQI in older adults

The PSQI as a screening tool for sleep dysfunction in clinical and non-clinical samples: A systematic review and meta-analysis

Brief version of the PSQI (B-PSQI) and measurement invariance across gender and age in a population-based sample

Psychometric evaluation of the PSQI
PSQI FAQs

Is the PSQI reliable/valid?

Yes! For more information on the validity/reliability of the PSQI, please refer to the original PSQI article linked in Documents.

Are PSQI translations reliable/valid?

Yes! PSQI translations have received the Linguistic Validation Certificate. This confirms that the translations are…

Conceptually equivalent to the original and comparable across languages; Culturally relevant to the context of the target country; Easily understood by the people to whom the translated instrument is administered.

 

For more information on the linguistic validity of PSQI translations, email vlachosc@upmc.edu

The PSQI is only validated for the time frame specified in the PSQI (monthly assessment). If you collect in a different time frame, the instrument will no longer be considered validated.

Can I modify the assessment time frame?

Documents for Download

Interested in using the PSQI? Request Form 

(If you are interested in using the PSQI for any case, you must fill out the request form)

Examples of using the PSQI includes (and is not limited to):

  • School project
  • Thesis (Graduate, undergraduate, high school)
  • Non-commercial research
  • Commercial research
  • Use in clinic
  • Use in Electronic Medical Record
  • Reprinting entire instrument in a journal

You do NOT need to submit a request to use the PSQI on yourself. Please simply download the instrument on your own.