Table 3.
Mortality hazard ratios from cox regression for middle-aged adults (n = 3128).
| Predictor | Death rate (%) | Hazard ratio (95% CI) | ||||
|---|---|---|---|---|---|---|
| Unadjusted | Age/sex-adjusted | Model 1a | Model 2b | Model 3c | ||
| TST | ||||||
| Q1 (< 331 min) | 92/776 (11.9) | 1.58 (1.20–2.08) | 1.54 (1.17–2.02) | 1.35 (1.02–1.79) | 1.34 (1.01–1.78) | 1.32 (0.95–1.84) |
| IQR (331 to < 414 min) | 115/1566 (7.3) | Ref | Ref | Ref | Ref | Ref |
| Q4 (≥ 414 min) | 25/786 (3.2) | 0.43 (0.28–0.66) | 0.49 (0.32–0.75) | 0.50 (0.32–0.77) | 0.49 (0.32–0.76) | 0.50 (0.31–0.79) |
| TIB | ||||||
| Q1 (< 400 min) | 74/779 (9.5) | 1.17 (0.88–1.57) | 1.20 (0.90–1.60) | 1.04 (0.78–1.40) | 1.03 (0.77–1.39) | 0.79 (0.55–1.12) |
| IQR (400 to < 477 min) | 122/1562 (7.8) | Ref | Ref | Ref | Ref | Ref |
| Q4 (≥ 477 min) | 36/787 (4.6) | 0.57 (0.39–0.83) | 0.59 (0.41–0.86) | 0.58 (0.40–0.85) | 0.59 (0.40–0.85) | 0.71 (0.48–1.04) |
| TST-restfulnessd | ||||||
| Q1 (< 331 min) | ||||||
| Unrestful | 44/372 (11.8) | 1.70 (1.16–2.47) | 1.66 (1.14–2.43) | 1.54 (1.05–2.27) | 1.57 (1.06–2.33) | 1.54 (1.01–2.33) |
| Restful | 48/404 (11.9) | 1.64 (1.36–2.38) | 1.65 (1.14–2.40) | 1.41 (0.96–2.07) | 1.37 (0.93–2.02) | 1.34 (0.87–2.05) |
| IQR (331 to < 414 min) | ||||||
| Unrestful | 47/594 (7.9) | 1.15 (0.79–1.67) | 1.22 (0.84–1.78) | 1.27 (0.87–1.86) | 1.28 (0.87–1.88) | 1.28 (0.87–1.89) |
| Restful | 68/972 (7.0) | Ref | Ref | Ref | Ref | Ref |
| Q4 (≥ 414 min) | ||||||
| Unrestful | 8/253 (3.2) | 0.44(0.20–0.95) | 0.51 (0.24–1.11) | 0.53 (0.24–1.16) | 0.53 (0.24–1.17) | 0.55 (0.24–1.21) |
| Restful | 17/533 (3.2) | 0.46 (0.27–0.79) | 0.53 (0.31–0.91) | 0.56 (0.32–0.95) | 0.54 (0.32–0.93) | 0.55 (0.32–0.97) |
| TIB-restfulnesse | ||||||
| Q1 (< 400 min) | ||||||
| Unrestful | 29/297 (9.8) | 1.37 (0.88–2.12) | 1.43 (0.92–2.22) | 1.29 (0.82–2.02) | 1.30 (0.83–2.05) | 0.96 (0.58–1.59) |
| Restful | 45/482 (9.3) | 1.28 (0.88–1.88) | 1.32 (0.90–1.94) | 1.15 (0.78–1.70) | 1.14 (0.77–1.68) | 0.86 (0.56–1.34) |
| IQR (400 to < 477 min) | ||||||
| Unrestful | 56/631 (8.9) | 1.30 (0.90–1.86) | 1.34 (0.93–1.93) | 1.40 (0.97–2.01) | 1.41 (0.97–2.04) | 1.33 (0.91–1.93) |
| Restful | 66/931 (7.1) | Ref | Ref | Ref | Ref | Ref |
| Q4 (≥ 477 min) | ||||||
| Unrestful | 13/291 (4.5) | 0.64 (0.36–1.17) | 0.68 (0.37–1.22) | 0.67 (0.37–1.22) | 0.67 (0.37–1.22) | 0.74 (0.41–1.36) |
| Restful | 23/496 (4.6) | 0.64 (0.39–1.03) | 0.67 (0.41–1.08) | 0.67 (0.41–1.08) | 0.67 (0.42–1.09) | 0.81 (0.49–1.33) |
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 = 0.85 for interaction between categorical TST and sleep restfulness variables.
eP = 0.91 for interaction between categorical TIB and sleep restfulness variables.