Table 3.
Participant characteristics
| All participants (N = 114) |
PCMM (n = 56) |
IRRI (n = 58) |
|
|---|---|---|---|
| Demographic characteristics | |||
| Age at screen, mean (SD) | 41.6 (9.5) | 41.4 (9.7) | 41.8 (9.5) |
| Education: ≥ college or technical degree, n (%) | 72 (63.2) | 35 (62.5) | 37 (63.8) |
| Clinical characteristics, mean (SD) | |||
| Age of onset (n = 113) | 18.9 (6.4) | 19.1 (6.4) | 18.6 (6.4) |
| Hamilton 17-item Rating Scale for Depression score | 5.2 (3.5) | 5.3 (4.0) | 5.1 (2.0) |
| Young Mania Rating Scale score | 1.8 (2.1) | 1.7 (2.2) | 1.9 (2.0) |
| Work and Social Adjustment Scale score | 13.4 (9.4) | 12.5 (9.2) | 14.2 (9.6) |
| Medications, n (%) | |||
| Taking sedatives or hypnotics | 13 (11.4) | 7 (12.5) | 6 (10.3) |
| Inflammatory characteristics (n = 102) | |||
| CRP (mg/L), mean (SD) | 4.1 (5.7) | 3.7 (4.7) | 4.5 (6.5) |
| IL6 (pg/mL), mean (SD) | 1.7 (1.4) | 1.6 (1.4) | 1.8 (1.4) |
| CRP > 3 mg/L, n (%) | 35 (34.3) | 19 (38.8) | 16 (30.2) |
| Mean of actigraphy sleep variables, (n = 104), mean (SD) | |||
| Total sleep time (min) | 420.9 (82.0) | 406.3 (76.8) | 435.0 (84.9) |
| Sleep onset time | 00:06 (01:36) | 00:01 (01:43) | 00:11 (01:30) |
| Coefficient of variation of actigraphy sleep variablesa (n = 104), mean (SD) | |||
| Total sleep time (min) | 6.2 (3.3) | 6.8 (3.9) | 5.7 (2.7) |
| Sleep duration (min) | 6.5 (3.2) | 7.1 (3.7) | 6.0 (2.7) |
| Sleep offset timeb | 0.4 (0.2) | 0.4 (0.2) | 0.3 (0.2) |
| Sleep midpointc | 0.3 (0.2) | 0.3 (0.2) | 0.3 (0.1) |
| Sleep onset time | 0.4 (0.3) | 0.4 (0.3) | 0.3 (0.2) |
| Wake after sleep onset (min) | 4.1 (2.0) | 4.4 (2.3) | 3.8 (1.7) |
| Daytime activity, mean (SD) | |||
| Physical activity (CAPA) (n = 96) | 121.7 (68.5) | 138.1 (67.0) | 111.0 (67.9) |
PCMM = psychiatric care with medical monitoring; IRRI = Integrated Risk Reduction Intervention; SD = standard deviation; CRP = c-reactive protein; CAPA = Clinical Assessment of Physical Activity.
We first calculated the instability and mean for each individual over seven days of actigraphy. Instability is a measure of variation that incorporates both the overall within-subject variance and the temporal dependence (autocorrelation) from night to night. To calculate the coefficient of variation, we then divided each individual’s instability by their mean. Because the coefficient of variation was highly skewed, this table shows the results after taking a square root transformation. Larger values represent more instability relative to the mean level.
t = 3.00, df = 81.9, p < 0.01
t = 2.59, df = 102, p = 0.01.