Table 5.
Actigraphic Measures of Sleep Duration and Continuity Averaged Over 7 Days by Baseline Characteristics.
| Baseline characteristic | Sample size | Time in bed, hours | Sleep duration, hours | Sleep fragmentation index | Sleep efficiency, % | Wake after sleep onset, minutes | Sleep Midpoint, hours:minutes | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Median (IQR) | pa | Median (IQR) | pa | Median (IQR) | pa | Median (IQR) | pa | Median (IQR) | p valuea | Median (IQR) | p valuea | ||
| Overall | 782 | 8.7 (1.1) | 7.4 (1.0) | 17.5 (7.6) | 85.2 (6.9) | 42.2 (23.4) | 3:38 (1:40) | ||||||
| Maternal age, years | |||||||||||||
| <22 | 148 | 9.1 (1.3) | <.0001 | 7.4 (1.1) | .5063 | 19.7 (8.7) | <.0001 | 82.0 (7.3) | <.0001 | 50.9 (31.3) | <.0001 | 4:33 (1:40) | <.0001 |
| 22–35 | 573 | 8.6 (1.1) | 7.5 (0.9) | 17.0 (7.2) | 85.8 (6.2) | 40.6 (21.1) | 3:25 (1:28) | ||||||
| >35 | 61 | 8.6 (1.1) | 7.3 (0.8) | 18.6 (8.2) | 84.6 (6.7) | 42.9 (20.9) | 2:59 (1:19) | ||||||
| Race/ethnicity | |||||||||||||
| Non-Hispanic white | 496 | 8.7 (1.0) | .1140 | 7.5 (0.9) | <.0001 | 16.4 (6.9) | <.0001 | 86.6 (5.5) | <.0001 | 39.9 (20.0) | <.0001 | 3:19 (1:19) | <.0001 |
| Non-Hispanic black | 92 | 8.9 (1.5) | 7.1 (1.0) | 21.5 (7.8) | 80.6 (6.5) | 54.6 (30.4) | 4:20 (1:54) | ||||||
| Hispanic | 122 | 8.8 (1.1) | 7.4 (1.0) | 18.5 (7.4) | 83.4 (7.6) | 47.0 (30.4) | 4:15 (2:11) | ||||||
| Asian | 28 | 8.5 (1.3) | 7.0 (1.0) | 18.3 (8.1) | 82.9 (7.8) | 43.9 (21.8) | 3:41 (1:23) | ||||||
| Other | 44 | 8.7 (1.4) | 7.4 (1.3) | 18.1 (9.5) | 83.1 (7.4) | 45.8 (24.6) | 4:00 (2:02) | ||||||
| BMI, kg/m2 | |||||||||||||
| <18.5 | 21 | 9.0 (1.1) | .0939 | 7.7 (0.8) | .3279 | 17.9 (8.8) | <.0001 | 84.5 (7.9) | <.0001 | 42.9 (35.7) | <.0001 | 5:04 (2:07) | .0029 |
| 18.5 to <25 | 391 | 8.6 (1.0) | 7.4 (0.9) | 16.7 (7.3) | 85.6 (6.9) | 39.4 (20.9) | 3:33 (1:22) | ||||||
| 25 to <30 | 194 | 8.8 (1.1) | 7.5 (0.9) | 17.5 (6.8) | 86.0 (5.7) | 42.8 (20.3) | 3:34 (1:41) | ||||||
| 30 to <35 | 98 | 8.7 (1.3) | 7.5 (1.0) | 18.4 (7.3) | 84.6 (6.6) | 42.3 (21.8) | 3:52 (2:02) | ||||||
| ≥35 | 68 | 8.8 (1.4) | 7.1 (1.2) | 20.9 (7.5) | 81.8 (7.8) | 54.7 (26.4) | 3:48 (2:26) | ||||||
| Insurance Status | |||||||||||||
| Commercial | 564 | 8.6 (1.1) | <.0001 | 7.4 (0.9) | .2713 | 16.5 (7.1) | <.0001 | 86.2 (6.2) | <.0001 | 39.6 (19.7) | <.0001 | 3:19 (1:19) | <.0001 |
| Government/ Self-pay | 214 | 9.0 (1.3) | 7.5 (1.2) | 19.8 (7.3) | 82.1 (7.5) | 51.7 (29.2) | 4:30 (1:54) | ||||||
| Smoked during 3 months prior to pregnancy: | |||||||||||||
| Yes | 113 | 8.8 (1.4) | .0818 | 7.3 (1.3) | .4537 | 19.5 (7.7) | <.0001 | 83.1 (6.0) | <.0001 | 48.3 (21.1) | <.0001 | 4:25 (2:15) | <.0001 |
| No | 669 | 8.7 (1.1) | 7.5 (0.9) | 17.0 (7.5) | 85.6 (6.9) | 41.0 (22.7) | 3:32 (1:28) | ||||||
Abbreviation: BMI, body mass index; IQR, Interquartile range.
aThe p values associated with Kruskal-Wallis tests.