Table 2.

Linear mixed model results stratified by feature set (FS) and outcome variable.

Outcome variable	FS1,a coefficient (P value)		FS2,b coefficient (P value)			FS3,c coefficient (P value)			FS4,d coefficient (P value)
	Anxiety	Depression	Anxiety	Depression	Anxiety		Depression	Anxiety		Depression
Week of study	0 (—e)	−0.16 (.14)	−0.0063 (.93)	−0.1826 (<.001)f	0.1122 (.22)		0.0659 (.62)	0.0643 (.43)		0.1803 (—)
Frequency	−0.0169 (.55)	−0.0632 (.14)	−0.0976 (.09)	−0.1304 (.004)f	−0.0438 (.12)		−0.086 (.004)f	−0.1747 (.001)		−0.5962 (—)
Days of use	0.0761 (.53)	−0.0737 (.74)	0.1757 (.08)	0.4565 (<.001)f	0.1047 (.38)		0.2374 (.25)	0.2909 (.02)		1.5607 (—)
Total duration	0.0003 (.67)	0.0021 (.12)	0.0011 (.63)	−0.0017 (.17)	0.0009 (.24)		0.0024 (.01)f	0.0026 (.24)		0.0009 (.68)
Mean duration	0.0237 (.17)	−0.027 (.24)	0.0071 (.78)	−0.0336 (.12)	0.0007 (.97)		−0.0637 (.03)f	−0.0092 (.66)		−0.1536 (—)
Duration SD	−0.0172 (.36)	0.0354 (.45)	0.0055 (.83)	−0.0093 (.66)	−0.0002 (.99)		0.098 (.02)f	0.0026 (.91)		0.0901 (—)
Minimum duration	−0.0459 (.02)f	0.032 (.37)	−0.0171 (.52)	0.0414 (.03)f	−0.0269 (.21)		0.0978 (.01)f	−0.0083 (.75)		0.0917 (<.001)f
Maximum duration	0.0007 (.92)	−0.0105 (.44)	−0.0047 (.70)	0.0248 (<0.001)f	0.0004 (.95)		−0.0215 (.05)f	−0.0006 (.96)		0.0386 (<.001)f

^aFS1: anxiety: α=.1, root mean square error 0.7396; depression: α=.1, root mean square error 0.7589.

^bFS2: anxiety: α=.7, root mean square error 0.8095; depression: α=.1, root mean square error 1.3954.

^cFS3: anxiety: α=.1, root mean square error 0.5128; depression: α=.1, root mean square error 0.4136.

^dFS4: anxiety: α=.1, root mean square error 0.5348; depression: α =.1, root mean square error 0.4547.

^eP value was not defined.

^fEffects with a P of <.05.