. 2020 Dec 18;7(12):e22423. doi: 10.2196/22423

Table 2.

Comparison of the baseline and 6-week mean scores on the PSS-10, GAD-7, and PHQ-9 scales for subscribers who completed both the baseline and sixth week surveys (N=766).

Measure	Responses, n^a	Scores			Mean difference (95% CI)	P value	t value	Effect size (Cohen d)
Measure	Responses, n^a	Baseline score, mean (SD)	Six-week score, mean (SD)	Change from baseline, %	Mean difference (95% CI)	P value	t value	Effect size (Cohen d)
PSS-10^b	684	20.35 (6.7)	19.51 (7.0)	4.1	–0.83 (0.42 to 1.24)	<.001	3.99	0.2
PHQ-9^c	630	8.94 (6.0)	8.74 (5.8)	2.2	–0.20 (–0.17 to 0.57)	.28	1.08	0.2
GAD-7^d	612	9.62 (5.6)	7.82 (5.2)	18.7	–1.80 (1.44 to 2.16)	<.001	9.86	0.4

^aNot all subscribers completed all three scales; therefore, n for each scale is less than the total N.

^bPSS-10: 10-Item Perceived Stress Scale.

^cPHQ-9: Patient Health Questionnaire-9.

^dGAD-7: Generalized Anxiety Disorder–7.