Table 3.

Correlation between digital biomarkers and 9-item Patient Health Questionnaire scores.

Category and digital biomarkers		Spearman rank correlation coefficient	P value	Adjusted P valuea
Heart rate metrics
	DHRb.cvc	0.121	.047	.18
	NHRd.0204.sde	0.262	<.001	.001
	NHR.0204.cv	0.257	<.001	.001
	NHR.0406.sd	0.182	.003	.04
	NHR.0406.cv	0.185	.002	.04
	NHR.0002.sd	0.149	.01	.08
	NHR.0002.cv	0.138	.02	.11
Circadian rhythm metrics: nonparametric
	ISf.stg.wdh	–0.165	.007	.049
	IS.hri.wd	–0.199	.001	.02
	ACj.st.60mk	–0.125	.04	.15
	AC.st.15m	–0.175	.004	.04
	AC.st.30m	–0.155	.01	.07
	AC.st.60m.wd	–0.159	.009	.06
	AC.st.15m.wd	–0.177	.004	.04
	AC.st.30m.wd	–0.177	.004	.04
	AC.hr.60m.wd	–0.150	.01	.08
	AC.hr.30m.wd	–0.144	.02	.08
	ICVl.st.wd	0.176	.004	.04
	ICV.hr	0.177	.004	.04
	ICV.hr.wd	0.237	<.001	.004
	peaks.st	–0.205	<.001	.02
	peaks.st.wd	–0.202	<.001	.02
Circadian rhythm metrics: cosinor based
	acrom.st	0.133	.03	.12
	F.st.wd	–0.121	.046	.17
	beta.hr	0.169	.006	.04
	acro.hr	0.146	.02	.09
	F.hr	–0.126	.04	.15
	beta.hr.wd	0.126	.04	.15
	acro.hr.wd	0.154	.01	.07
	F.hr.wd	–0.137	.03	.11
Sleep metrics
	sleep.offset	0.144	.02	.09
	sleep.midpoint	0.172	.005	.04
	sleep.offset.wd	0.134	.03	.12
	sleep.offset.wd.sd	0.199	.001	.02
	sleep.midpoint.wd	0.146	.02	.09
	sleep.midpoint.wd.sd	0.146	.02	.09

^aP values were adjusted for multiple testing correction. Only significant associations were reported.

^bDHR: daytime heart rate between 2 PM and 4 PM.

^ccv: coefficient of variation.

^dNHR: nighttime heart rate in a specified 2-hour time interval; 2 AM-4 AM (0204), 4 AM-6 AM (0406), and 12 AM-2 AM (0002).

^esd: standard deviation.

^fIS: interdaily stability.

^gst: steps based.

^hwd: weekdays based.

ⁱhr: heart rate based.

^jAC: autocorrelation.

^km: minutes; 15-minute, 30-minute, or 60-minute time interval in which raw data were aggregated.

^lICV: interdaily coefficient of variation.

^macro: acrophase.