Table 2.

Correlations between symptom severity score and features.

Category and features		r	N	P value
Mobility and activity
	Number of activities	.21	206	.002
	Maximum magnitude of accelerometer	−.22	220	.001
	Mean magnitude of accelerometer	−.28	220	<.001
	Median magnitude of accelerometer	−.24	220	<.001
	SD of accelerometer	−.25	220	<.001
	Fitbit steps	−.20	194	.007
	Fitbit distance	−.19	165	.01
	Fitbit floors	−.23	165	.003
	Fitbit minutes fairly active	−.17	165	.03
	Fitbit minutes very active	−.21	165	.006
	Fitbit maximum steps per minute	−.57	65	<.001
	Fitbit number of sedentary bouts	.52	65	<.001
	Fitbit maximum length sedentary bout	.44	65	<.001
	Fitbit mean length sedentary bout	.27	65	.03
	Fitbit number active bouts	.52	65	<.001
	Fitbit mean length active bout	−.29	65	.02
	Fitbit maximum steps active bout	−.43	65	<.001
	Fitbit mean step active bout	−.47	65	<.001
Sleep
	Fitbit minutes asleep	.33	141	<.001
	Fitbit minutes awake	.23	141	.006
	Fitbit number of awakenings	.29	141	<.001
	Fitbit time in bed	.22	141	.008
Phone usage
	Apps per minute	−.18	269	.003
	Duration of interaction with phone	.27	295	<.001
	Screen unlocks per minute	−.19	295	.001
Communication
	Number of missed calls	−.22	98	.03