OR (95% CI) for the association of sleep quality, a single item from the Pittsburgh Sleep Quality Index (PSQI) with knee pain outcomes stratified by baseline widespread pain status.
| Knee Pain Outcomes | Sleep Quality in Past Week in the PSQI | |||
|---|---|---|---|---|
| 0, 1 = Poor (Ref.) | 2 = Fairly Good | 3 = Very Good | P Trend | |
| Consistent frequent knee pain | ||||
| Cross-sectional association for prevalent consistent frequent knee pain, n = 4640 | ||||
| Knee, n/N (%)1 | 376/824 (45.6) | 887/2582 (34.4) | 342/1234 (27.7) | |
| OR (95% CI)2 | 1.0 (ref) | 0.84 (0.68–1.03) | 0.69 (0.54–0.90) | 0.005 |
| Longitudinal association for incident consistent frequent knee pain, n = 2646 | ||||
| Knee, n/N (%) | 88/385 (17.6) | 309/1503 (61.7) | 104/758 (20.8) | |
| OR (95% CI) | 1.0 (ref) | 1.07 (0.84–1.36) | 0.80 (0.60–1.07) | 0.08 |
| Knee pain worsening, n = 4658 | ||||
| Widespread pain absence, n = 2746 | ||||
| Knee, n/N (%) | 87/358 (24.3) | 304/1476 (20.6) | 159/912 (17.4) | |
| OR (95% CI) | 1.0 (ref) | 0.86 (0.62–1.21) | 0.70 (0.48–1.02) | 0.037 |
| Widespread pain presence, n = 1912 | ||||
| Knee, n/N (%) | 176/470 (37.4) | 359/1116 (32.1) | 87/326 (26.7) | |
| OR (95% CI) | 1.0 (ref) | 0.72 (0.54–0.96) | 0.53 (0.35–0.78) | < 0.01 |
↵1 No. knees: n (knees with pain worsening or incident joint pain) / N (total no. knees).
↵2 Model adjusted for age (yrs), sex (men vs women), race (white vs non-white), study site, BMI (kg/m2), education level (college and above vs below college), tobacco use (pack-yrs), Charlson Comorbidity Index (range 0–9), fatigue (10-point scale), CES-D depression indicator (yes, no), and prescription use of NSAID (yes, no). BMI: body mass index; CES-D: Center for Epidemiologic Studies Depression Scale; NSAID: nonsteroidal antiinflammatory drug.