Carnegie Mellon University

Sleep Habits


Miscellaneous Sleep Questions



Copyright Information

Not a copyrighted scale


To assess sleep quality and sleep duration

Type of Measure

Created for study


Using a 5-point frequency scale, participants estimate how often they feel rested when they wake from sleep.  Participants also provide the number of hours they typically sleep at night.


Hours of sleep:  open-ended

Frequency of feeling rested:  0=never, 1=almost never, 2=sometimes, 3=fairly often, 4=very often

Number of Items



  • How many hours, on the average do you sleep at night?  (sleep duration)
  • How often do you feel “rested” from your night’s sleep? (sleep quality)


None available


The Pittsburgh Sleep Quality Index  (PSQI)



Copyright Information

Please contact Dr. Daniel Buysse ( for permission to use this instrument.

The entire scale, complete scoring instructions, and additional copyright information are available at the University of Pittsburgh Sleep Medicine Institute’s PSQI page.

Primary Reference

Buysse, D. J., Reynolds, C. F., Monk, T. H., Berman, S. R., & Kupfer, D. J. (1989). The Pittsburgh Sleep Quality Index. Psychiatry Research, 28, 193-213.


To assess typical sleep habits and subjective sleep quality.

Type of Measure

The established 24-item PSQI was administered in PCS1. Modified versions of the scale were administered in the subsequent three studies.  


The sleep questionnaires administered in PCS2 and PMBC included only select items from the PSQI (see Sample Items below), as well as additional items asking participants to estimate the number of minutes of sleep they typically lose during the night.  A question about the frequency of naps taken during the day was added in PMBC because there is some evidence to suggest that daytime sleep may be a predictor of mortality.


PCS3 included an 18-item version of the PSQI that excluded 1 item asking whether the participant has a sleep partner, and 5 items asking for evaluation of the participant’s sleep elicited from the sleep partner or a roommate.  A further modification was that respondents were instructed to use the past 2 weeks as the reference period rather than the past month (as indicated in the original PSQI).


Participants respond to questions about usual bed- and wake-times, subjective sleep quality, sleep latency, minutes of sleep lost during the night (PCS2, PMBC), frequencies of specific types of sleep disturbances (PCS1, PCS3), and frequency of having difficulty staying awake (PCS1, PMBC, PCS3).  In PCS1, bed partners or roommates respond to items regarding the frequency with which they have observed participant sleep problems (e.g., snoring, restlessness).  The reference period used in PCS1, PCS2, and PMBC was the past month (consistent with the original scale), and in PCS3, the past two weeks.


The PSQI is comprised of a mix of open- and closed-ended response items.  All closed-ended items are rated using 4-point scales.

Sleep quality:  0 = very good, 1 = fairly good, 2 = fairly bad, 3 = very bad.

Problems keeping up enthusiasm:  0 = no problem, 1 = very slight problem, 2 = somewhat of a problem, 3 = very big problem.

Frequency items:  0 = never, 1 = less than once a week, 2 = once or twice a week, 3 = three or more times a week.

Number of Items

24 (PCS1); 6 (PCS2); 8 (PMBC); 18 (PCS3)

Sample Items

In addition to PSQI items 1, 2, 3, and 6, PCS2 and PMBC included the following two items:
  • On an average night during the past month, how many minutes of sleep did you lose because you woke up in the middle of the night? (open-ended)
  • On an average night during the past month, how many minutes of sleep did you lose because you woke earlier than your usual time to get up? (open-ended)
PMBC also included PSQI item 8 as well as the following additional item that was rated using the frequency response scale described above:  

  • During the past month, how often have you taken naps during the day?


Total time in bed:  difference (minutes) between reported bed- and wake-times.

Sleep latency:  response to item asking for minutes needed to fall asleep

Sleep lost (PCS2, PMBC):  minutes lost due to waking up at night + minutes lost due to early wakening

Sleep Duration:
  • PCS2, PMBC:  [total time in bed – sleep latency – sleep lost] / 60
  • PCS1, PCS3:  response to item asking for hours of actual sleep per night
Sleep Efficiency2:  [sleep duration / total time in bed] x 100

Sleep Quality:  response to item; higher values indicate poorer sleep.

1For additional sleep-related questions, see also Daily Interviews

2The distribution of sleep efficiency is typically very negatively skewed (i.e., toward more efficient sleep) and thus dichotomized at 80%.