Table 4.
Estimated differences in sleep indices between patients with BD, UR and HC (n=366)
| Model 1* | Model 2* | |||||||||||||||||
| BD | UR | HC | BD/HC | BD/UR | UR/HC | BD | UR | HC | BD/HC | BD/UR | UR/HC | |||||||
| Mean | 95% CI | Mean | 95% CI | Mean | 95% CI | P value | P value | P value | Mean | 95% CI | Mean | 95% CI | Mean | 95% CI | P value | P value | P value | |
| Self-reported smartphone-based sleep BD=203, UR=54, HR=109 |
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| Bedtime (hours:min) | 00:25 | 00:15 to 00:34 | 23:59 | 23:41 to 00:16 | 23:52 | 23:39 to 00:05 | <0.001 | 0.003 | 0.56 | 00:23 | 00:13 to 00:32 | 23:49 | 23:32 to 00:05 | 23:51 | 23:38 to 00:04 | <0.001 | <0.001 | 0.80 |
| Wake-up time (hours:min) | 08:21 | 08:11 to 08:30 | 7.53 | 7.35 to 8.11 | 7.40 | 7.26 to 7.54 | <0.001 | 0.003 | 0.25 | 8.18 | 8.08 to 8.27 | 7.40 | 7.23 to 7.57 | 7.39 | 7.26 to 7.51 | <0.001 | <0.001 | 0.89 |
| Mid-sleep (hours:min) | 04:23 | 04:14 to 04:32 | 03:56 | 03:39 to 04:18 | 03:46 | 03:34 to 03:58 | <0.001 | 0.001 | 0.36 | 04:21 | 04:12 to 04:29 | 03:45 | 03:29 to 04:00 | 3.45 | 3.33 to 3.56 | <0.001 | <0.001 | 0.99 |
| Total sleep time (hours:min) | 07:56 | 07:49 to 08:03 | 07:53 | 07:39 to 08:06 | 07:47 | 07:38 to 07:57 | 0.15 | 0.74 | 0.46 | 07:56 | 07:48 to 08:03 | 07:51 | 07:37 to 08:05 | 07:47 | 07:38 to 07:57 | 0.17 | 0.55 | 0.65 |
| Total sleep time variability† (hours) | 2.09 | 1.99 to 2.19 | 1.86 | 1.68 to 2.04 | 1.73 | 1.59 to 1.87 | <0.001 | 0.014 | 0.26 | 2.10 | 2.00 to 2.20 | 1.80 | 1.63 to 1.98 | 1.77 | 1.63 to 1.90 | <0.001 | 0.001 | 0.73 |
| Wake-up after 08:00‡ | 55.9 | 52.1 to 59.8 | 43.3 | 35.8 to 50.8 | 42.7 | 37.5 to 48.0 | <0.001 | 0.002 | 0.90 | 57.4 | 53.7 to 61.2 | 40.1 | 33.1 to 47.2 | 45.0 | 40.1 to 50.0 | <0.001 | <0.001 | 0.26 |
| Hours slept between 12:00 and 06:00 (hours:min)§ | 04:59 | 04:53 to 05:05 | 05:15 | 05:05 to 05:25 | 05:24 | 05:16 to 05:32 | <0.001 | 0.003 | 0.15 | 05:01 | 04:55 to 05:07 | 05:21 | 05:10 to 05:31 | 05:25 | 05:17 to 05:33 | <0.001 | <0.001 | 0.50 |
| Daily variability in hours slept between 12:00 and 06:00¶ (hours) | 1.47 | 1.38 to 1.56 | 1.22 | 1.05 to 1.40 | 1.30 | 1.18 to 1.43 | 0.032 | 0.011 | 0.46 | 1.50 | 1.41 to 1.59 | 1.16 | 1.00 to 1.33 | 1.36 | 1.24 to 1.47 | 0.042 | 0.001 | 0.063 |
| Pittsburgh Sleep Quality Index BD=241, UR=81, HC=163 |
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| Total PSQI score** | 8.66 | 8.23 to 9.09 | 5.13 | 4.36 to 5.90 | 3.81 | 3.26 to 4.36 | <0.001 | <0.001 | 0.006 | 8.56 | 8.12 to 8.99 | 5.01 | 4.24 to 5.78 | 3.77 | 3.22 to 4.32 | <0.001 | <0.001 | 0.011 |
| Automatically smartphone-generated measures of sleep††
BD=71 UR=15, HC=32 |
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| Hours with screen turned off between 12:00 and 06:00 am | 05:28 | 05:21 to 05:35 | 05:40 | 05:25 to 05:54 | 05:39 | 05:28 to 05:49 | 0.082 | 0.13 | 0.94 | 05:29 | 05:22 to 05:36 | 5.41 | 05:26 to 05:56 | 05:39 | 05:29 to 05:49 | 0.10 | 0.12 | 0.82 |
| Variability in hours slept between 12:00 and 06:00 | 1.17 | 1.01 to 1.34 | 1.18 | 0.84 to 1.53 | 1.07 | 0.81 to 1.32 | 0.49 | 0.96 | 0.59 | 1.16 | 0.99 to 1.33 | 1.14 | 0.79 to 1.49 | 1.09 | 0.84 to 1.34 | 0.62 | 0.90 | 0.81 |
| Screen turned on (number/daily between 12:00 and 06:00) | 5.71 | 4.43 to 7.0 | 5.28 | 2.48 to 8.07 | 4.40 | 2.49 to 6.30 | 0.26 | 0.78 | 0.61 | 5.50 | 4.21 to 6.80 | 4.79 | 2.02 to 7.55 | 4.39 | 2.53 to 6.25 | 0.34 | 0.64 | 0.81 |
| Sleep measures on HAMD and YMRS BD=337, UR=91, HC=183 |
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| HAMD subitems 4–6 | 2.33 | 2.12 to 2.52 | 1.24 | 0.85 t o 1.63 | 0.67 | 0.40 to 0.95 | <0.001 | <0.001 | 0.019 | 2.26 | 2.05 to 2.46 | 1.17 | 0.79 to 1.56 | 0.65 | 0.38 to 0.92 | <0.001 | <0.001 | 0.029 |
| YMRS subitem 4 | 0.39 | 0.31 to 0.46 | 0.14 | −0.08 to 0.29 | 0.07 | −0.03 to 0.17 | <0.001 | 0.002 | 0.44 | 0.38 | 0.31 to 0.46 | 0.13 | −0.02 to 0.27 | 0.08 | −0.02 to 0.18 | <0.001 | 0.002 | 0.61 |
*Model 1: Unadjusted, Model 2: Adjusted for age and sex.
†Day-to-day variability in sleep duration calculated by using the RMSSD score.
‡Proportion of days participants woke up after 08:00.
§Hours where the participants had self-reported sleep between12:00 and 06:00.
¶Day-to-day variability in hours slept between 12:00 and 06:00, calculated by using the RMSSD score.
**PSQI: the total score, all visits are used in the calculations.
††Automatically smartphone-generated sleep measures.
HAMD: sum of items 4–6 addressing sleep.
YMRS: subitem 4 addressing sleep.
BD, bipolar disorder; HAMD, Hamilton Depression Rating Scale; HC, healthy control individuals; PSQI, Pittsburgh Sleep Quality Index; UC, unaffected first-degree relatives; YMRS, Young Mania Rating Scale.