| MEASUREMENT PROPERTIES | |
| Limitations | >=5 European languages (English) |
| Observations |
Limited data are available. When assessed in an Ethiopian cohort of community-dwelling adults, no floor or ceiling effect was found |
| 1. RELIABILITY | |
| A. Internal Consistency | Tested |
| Cronbach's (Describe) |
Cronbach’s α for global PSQI scores ranged from 0.67 to 0.83, depending on the population sampled. In a cohort of patients with rheumatoid arthritis (RA), Cronbach’s α was 0.73 |
| B. Reliability intraobserver or test-retest | Tested |
| Continuous scores: intraclass correlation coefficient (ICC) Dichotomus: Cohen kappa (Describe) |
The intraclass correlation coefficient (ICC) has been reported to be 0.90 for 2 days between testing and 0.86 for a period of 2 to 6 weeks between testing |
| C. Reliability interobserver or Measurement error | Not Tested |
| Standard error of measurement (SEM), smallest detectable change (SDC) or Limits of agreement (LoA) (Describe) |
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| 2. VALIDITY | |
| A. Content validity: face validity | Tested |
| Expert opinion (relevance and comprehensiveness) (Describe) |
PSQI items were developed based on clinical judgement rather than focus groups of all stakeholders, including poor sleepers. However, the PSQI items capture a wide range of issues related to sleep quality, and the content appears suitable to accomplish its aim to distinguish good from poor sleepers |
| B. Construct Validity: Structural validity |
Tested |
| Hypotheses-testing | Tested |
| Cross-cultural validity | Tested |
| Brief Description |
A short PSQI consisting of 13 items from five of the seven components in the original PSQI has been validated in a population of college students |
| C. Criterion validity | Tested |
| Comparison with a 'gold standard' Continuous scores: correlations, ROC curves Dichotomus: Sensitivity & Specificity (Describe) |
Based on a gold standard of clinical evaluation, the PSQI distinguished good sleepers from poor sleepers in the original validation article with reasonable sensitivity and specificity (see Score interpretation section above). Later work has challenged the single-factor model, in which the seven subcomponents are summed into a single PSQI score to discriminate good from poor sleepers, and suggests that a three-factor model is statistically favored and may better capture the multidimensionality of sleep assessed by the instrument. The three-factor latent groups proposed by this study were 1) sleep efficiency, 2) perceived sleep quality, and 3) daily disturbances. Several others have also proposed two- and threefactor models for the PSQI |