Table 2.
Effects of PHQ-8a and seasonality on wearable-measured circadian rhythm features estimated by mixed-effects regression models (models 1b and 2c).d
| Feature | Model 1 | Model 2 | Likelihood ratio test (P values) | ||||
|
|
PHQ-8, β1 (SE) | PHQ-8, β1 (SE) | Spring, β2 (SE) | Summer, β2 (SE) | Autumn, β2 (SE) |
|
|
| Sleep duration | 0.51 (0.14)*** | 0.46 (0.14)*** | –6.48 (1.32)*** | –16.63 (1.31)*** | –6.13 (1.31)*** | <.001 | |
| Sleep onset | 0.52 (0.17)** | 0.55 (0.17)** | 3.68 (1.61)* | 7.16 (1.59)*** | –4.64 (1.60)** | <.001 | |
| Sleep offset | 1.13 (0.15)*** | 1.12 (0.15)*** | –0.25 (1.44) | –6.91 (1.43)*** | –8.32 (1.43)*** | <.001 | |
| Sleep variability | 0.97 (0.14)*** | 0.96 (0.14)*** | –8.48 (1.36)*** | –5.29 (1.35)*** | –2.82 (1.35)* | <.001 | |
| Daily step | –94.71 (6.43)*** | –93.61 (6.41)*** | –19.21 (61.28) | 394.46 (60.81)*** | 186.16 (60.75)** | <.001 | |
| Step IVe | 0.001 (0.0006) | 0.0007 (0.0006) | 0.001 (0.006) | –0.026 (0.006)*** | –0.021 (0.006)*** | .006 | |
| Step ISf | –0.001 (0.0002)*** | –0.001 (0.0002)*** | 0.002 (0.002) | –0.006 (0.002)* | 0.004 (0.002) | .007 | |
| L5 onsetg | 0.43 (0.21)* | 0.43 (0.21)* | –1.10 (2.13) | –3.84 (2.12) | –3.98 (2.12) | .002 | |
| M10 onseth | 0.66 (0.25)** | 0.73 (0.25)** | 11.94 (2.45)*** | 20.51 (2.43)*** | 1.61 (2.44) | <.001 | |
| HRi MESORj | –0.03 (0.01)*** | –0.03 (0.01)*** | –0.47 (0.09)*** | –0.01 (0.09) | 0.04 (0.09) | <.001 | |
| HR amplitude | –0.04 (0.01)*** | –0.04 (0.01)*** | 0.19 (0.05)*** | 0.92 (0.05)*** | 0.39 (0.05)*** | <.001 | |
| HR acrophase | 0.51 (0.24)* | 0.71 (0.22)** | 43.35 (2.15)*** | 67.94 (2.13)*** | 24.09 (2.13)*** | <.001 | |
aPHQ-8: 8-item Patient Health Questionnaire.
bModel 1: Circadian rhythm = β1 PHQ‑8 + COVs.
cModel 2: Circadian rhythm = β1 PHQ‑8 + β2 season + COVs, where COVs represents covariates mentioned in the Methods section. Note that winter is the reference season.
dThe exact P values are reported in the main text.
eIV: intradaily variability.
fIS: interdaily stability.
gL5 onset: the onset of least active continuous 5-hour period.
hM10 onset: the onset of the most active continuous 10-hour period.
iHR: heart rate.
jHR MESOR: midline estimating statistic of the fitted cosine wave for heart rate.
*P<.05, **P<.01, ***P<.001.