Table 4.
Mortality hazard ratios from cox regression for older adults (n = 2676).
| Predictor | Death rate (%) | Hazard ratio (95% CI) | ||||
|---|---|---|---|---|---|---|
| Unadjusted | Age/sex-adjusted | Model 1a | Model 2b | Model 3c | ||
| TST | ||||||
| Q1 (< 310 min) | 299/664 (45.0) | 1.17 (1.01–1.34) | 1.12 (0.97–1.29) | 1.04 (0.90–1.20) | 1.01 (0.88–1.17) | 1.08 (0.92–1.27) |
| IQR (310 to < 396 min) | 547/1339 (40.9) | Ref | Ref | Ref | Ref | Ref |
| Q4 (≥ 396 min) | 228/673 (33.9) | 0.80 (0.68–0.93) | 0.90 (0.77–1.05) | 0.89 (0.76–1.04) | 0.88 (0.75–1.03) | 084 (0.72–1.00) |
| TIB | ||||||
| Q1 (< 404 min) | 270/667 (40.5) | 1.08 (0.93–1.25) | 1.09 (0.94–1.26) | 1.07 (0.92–1.24) | 1.05 (0.91–1.22) | 0.91 (0.76–1.08) |
| IQR (404 to < 482 min) | 508/1336 (38.0) | Ref | Ref | Ref | Ref | Ref |
| Q4 (≥ 482 min) | 296/673 (44.0) | 1.25 (1.08–1.44) | 1.22 (1.05–1.41) | 1.18 (1.02–1.37) | 1.18 (1.02–1.36) | 1.25 (1.08–1.46) |
| TST-restfulnessd | ||||||
| Q1 (< 310 min) | ||||||
| Unrestful | 113/268 (42.2) | 1.05 (0.85–1.30) | 1.10 (0.89–1.36) | 1.03 (0.83–1.28) | 1.02 (0.82–1.27) | 1.09 (0.86–1.36) |
| Restful | 186/396 (47.0) | 1.17 (0.98–1.40) | 1.11 (0.93–1.33) | 1.05 (0.88–1.26) | 1.02 (0.82–1.27) | 1.08 (0.89–1.32) |
| IQR (310 to < 396 min) | ||||||
| Unrestful | 145/387 (37.5) | 0.87 (0.71–1.05) | 0.97 (0.80–1.18) | 1.00 (0.82–1.22) | 1.01 (0.83–1.23) | 1.01 (0.83–1.24) |
| Restful | 401/952 (42.1) | Ref | Ref | Ref | Ref | Ref |
| Q4 (≥ 396 min) | ||||||
| Unrestful | 52/136 (38.2) | 0.89 (0.65–1.20) | 1.07 (0.79–1.44) | 1.01 (0.74–1.39) | 0.99 (0.72–1.36) | 0.95 (0.69–1.31) |
| Restful | 176/537 (32.8) | 0.73 (0.61–0.88) | 0.85 (0.71–1.01) | 0.86 (0.71–1.03) | 0.86 (0.71–1.03) | 0.82 (0.68–0.99) |
| TIB-restfulnesse | ||||||
| Q1 (< 404 min) | ||||||
| Unrestful | 87/221 (39.4) | 1.00 (0.79–1.27) | 1.04 (0.82–1.32) | 0.99 (0.78–1.26) | 0.99 (0.78–1.27) | 0.84 (0.64–1.09) |
| Restful | 184/446 (41.3) | 1.08 (0.90–1.29) | 1.11 (0.93–1.33) | 1.10 (0.92–1.32) | 1.07 (0.89–1.29) | 0.93 (0.76–1.14) |
| IQR (404 to < 482 min) | ||||||
| Unrestful | 143/397 (36.0) | 0.93 (0.76–1.14) | 1.00 (0.82–1.23) | 0.99 (0.80–1.22) | 0.98 (0.80–1.21) | 0.95 (0.77–1.17) |
| Restful | 365/939 (38.9) | Ref | Ref | Ref | Ref | Ref |
| Q4 (≥ 482 min) | ||||||
| Unrestful | 81/173 (46.8) | 1.37 (1.07–1.75) | 1.51 (1.18–1.93) | 1.52 (1.18–1.94) | 1.51 (1.17–1.93) | 1.57 (1.23–2.01) |
| Restful | 215/500 (43.0) | 1.17 (0.99–1.39) | 1.13 (0.95–1.34) | 1.08 (0.91–1.29) | 1.07 (0.90–1.28) | 1.14 (0.95–1.36) |
CI confidence interval, IQR interquartile range, Q1 lowest quartile, Q4 highest quartile, Ref reference, TIB time in bed, TST total sleep time.
aModel 1 included age, sex, race (Caucasian vs. other), body mass index, smoking status, apnea hypopnea index with 4% desaturation, sleep time with saturated oxygen below 80%, stroke, myocardial infarction, hypertension, diabetes, and physical functioning standardized score on the Short Form 36 Health Survey.
bModel 2 included Model 1 plus antidepressants, benzodiazepines, Epworth Sleepiness Scale score, number of daytime naps per week, weekend-weekday difference in habitual sleep duration, insomnia or poor sleep, and percent time in rapid eye movement sleep.
cModel 3 included Model 2 plus TIB in TST/TST-restfulness models or TST in TIB/TIB-restfulness models.
dP = 0.22 for interaction between categorical TST and sleep restfulness variables.
e P = 0.28 for interaction between categorical TIB and sleep restfulness variables.