Table 2.
Sleep properties at baseline and their change at follow-up.
| Total | βAge† | P† | Women | Men | βW/M‡ | P‡ | |
|---|---|---|---|---|---|---|---|
| Baseline measure | |||||||
| PSQI, score | 4.2 (2.3) | 0.03 | <.001 | 4.4 (2.4) | 4.0 (2.2) | 0.67 | <.001 |
| Sleep latency, min | 16.0 (16.9) | 0.16 | .001 | 17.0 (18.1) | 15.0 (15.6) | 4.22 | <.001 |
| HSE, % | 94.2 (10.6) | −0.24 | <.001 | 94.3 (11.2) | 94.1 (10.0) | −0.34 | .508 |
| Time in bed, h | 6.7 (1.2) | 0.00 | .455 | 6.6 (1.3) | 6.9 (1.1) | −0.18 | .001 |
| Sleep duration, h | 6.3 (1.2) | −0.01 | <.001 | 6.2 (1.2) | 6.4 (1.2) | −0.21 | <.001 |
| MSFsc, 24-h | 3:05 (1:11) | −0:03 | <.001 | 2:59 (1:07) | 3:12 (1:14) | −0:03 | .307 |
| Midsleep time (F), 24-h | 3:15 (1:15) | −0:04 | <.001 | 3:11 (1:12) | 3:18 (1:18) | 0:03 | .289 |
| Midsleep time (W), 24-h | 2:54 (1:05) | −0.02 | <.001 | 2:48 (0:59) | 2:59 (1:10) | −0:02 | .346 |
| Social jetlag, 24-h | 0:24 (0:40) | −0:01 | <.001 | 0:26 (0:37) | 0:23 (0:42) | 0:05 | .004 |
| Longitudinal change | |||||||
| ΔPSQI, score | 0.7 (3.0) | 0.02 | .011 | 0.9 (3.1) | 0.5 (2.8) | 0.80 | <.001 |
| ΔSleep latency, min | 1.2 (22.7) | 0.22 | <.001 | 3.5 (26.7) | −1.1 (17.6) | 6.86 | <.001 |
| ΔHSE, % | −4.0 (14.4) | −0.26 | <.001 | −5.6 (14.9) | −2.3 (13.7) | −3.71 | <.001 |
| ΔTime in bed, h | 0.3 (1.4) | 0.02 | <.001 | 0.4 (1.4) | 0.2 (1.4) | 0.02 | .769 |
| ΔSleep duration, h | 0.0 (1.4) | 0.00 | .561 | −0.1 (1.4) | 0.0 (1.3) | −0.23 | <.001 |
| ΔMSFsc, 24-h | −0:29 (1:22) | −0:01 | <.001 | −0:19 (1:16) | −0:38 (1:26) | 0:09 | .006 |
| ΔMidsleep time (F), 24-h | −0:35 (1:19) | −0:01 | <.001 | −0:29 (1:12) | −0:42 (1:25) | 0:08 | .013 |
| ΔMidsleep time (W), 24-h | −0:23 (1:12) | −0:01 | <.001 | −0:16 (1:07) | −0:31 (1:16) | 0:07 | .023 |
| ΔSocial jetlag, 24-h | −0:11 (0:54) | −0:01 | <.001 | −0:11 (0:55) | −0:11 (0:53) | 0:03 | .126 |
The adjusted mean (SD) values at baseline (upper portion) and change at follow-up (lower portion) are shown. βAge† and βW/M‡ were computed in the same model. βAge† (presented with its corresponding P†) is the estimated association of age to the corresponding sleep characteristic after adjusting for sex, body mass index (kg/m2), smoking intensity (pack-years), alcohol consumption (g/d), hypertension, diabetes mellitus, and occupation. For longitudinal comparisons, additional adjustments for the variable at baseline and the visit interval (years) were made. βW/M‡ (presented with its corresponding P‡) reflects the association of the measures in women relative to men. F = free days, HSE = habitual sleep efficiency, MSFsc = mid-sleep time on free days corrected for sleep debt on weekdays, PSQI = Pittsburgh Sleep Quality Index, SD = standard deviation, W = workdays, Δ = change.