. 2021 Feb 23;78(6):1–7. doi: 10.1001/jamapsychiatry.2021.0113

Table 2. Loneliness, Mental and General Health, and Social Connections in Intervention and Control Arms at Baseline and After 4 Weeks of Intervention.

Measurement	Time	Control	Intervention	Group difference at the postassessment stage		P value for group × days^b	ICC (95% CI)^c
Measurement	Time	Mean (95% CI)	Mean (95% CI)	Mean (95% CI)	Cohen d^a	P value for group × days^b	ICC (95% CI)^c
UCLA	Pre	6.5 (6.1 to 6.9)	6.5 (6.1 to 6.9)	1.1 (.50 to 1.7)	0.48	<.001	0.72 (0.62 to 0.80)
UCLA	Post	6.3 (5.9 to 6.8)	5.2 (4.8 to 5.6)	1.1 (.50 to 1.7)	0.48	<.001	0.72 (0.62 to 0.80)
De Jong	Pre	2.5 (2.1 to 2.8)	2.4 (2.1 to 2.8)	0.32 (−0.20 to 0.81)	0.17	.06	0.80 (0.75 to 0.84)
De Jong	Post	2.5 (2.1 to 2.8)	2.2 (1.8 to 2.5)	0.32 (−0.20 to 0.81)	0.17	.06	0.80 (0.75 to 0.84)
LSNS	Pre	13.1 (11.9 to 14.3)	12.6 (11.3 to 13.8)	1.1 (−.67 to 3.0)	0.17	.37	0.80 (0.72 to 0.86)
LSNS	Post	13.0 (11.8 to 14.3)	11.9 (10.6 to 13.2)	1.1 (−.67 to 3.0)	0.17	.37	0.80 (0.72 to 0.86)
PHQ-8	Pre	6.2 (5.3 to 7.1)	6.3 (5.5 to 7.1)	1.5 (0.22 to 2.7)	0.31	<.001	0.78 (0.72 to 0.83)
PHQ-8	Post	6.3 (5.3 to 7.2)	4.8 (4.0 to 5.6)	1.5 (0.22 to 2.7)	0.31	<.001	0.78 (0.72 to 0.83)
PHQ-8 ≥ 5, proportion (95% CI)^d	Pre	0.58 (0.48 to 0.66)	0.59 (0.50 to 0.68)	0.09 (−0.03 to 0.23)	NA	.05	NA
PHQ-8 ≥ 5, proportion (95% CI)^d	Post	0.54 (0.44 to 0.63)	0.44 (0.34 to 0.54)	0.09 (−0.03 to 0.23)	NA	.05	NA
GAD-7	Pre	5.8 (4.8 to 6.9)	5.9 (4.9 to 6.9)	1.8 (0.44 to 3.2)	0.35	<.001	0.73 (0.66 to 0.78)
GAD-7	Post	6.0 (4.9 to 7.0)	4.1 (3.2 to 5.0)	1.8 (0.44 to 3.2)	0.35	<.001	0.73 (0.66 to 0.78)
GAD-7 ≥ 5, proportion (95% CI)^d	Pre	0.49 (0.40 to 0.58)	0.50 (0.41 to 0.59)	0.14 (0.01 to 0.27)	NA	.02	NA
GAD-7 ≥ 5, proportion (95% CI)^d	Post	0.50 (0.40 to 0.59)	0.36 (0.27 to 0.45)	0.14 (0.01 to 0.27)	NA	.02	NA
SF-12 physical health	Pre	32.0 (29.9 to 34.1)	32.0 (29.8 to 33.2)	0.51 (−2.4 to 3.4)	0.05	.98	0.75 (0.69 to 0.80)
SF-12 physical health	Post	33.9 (31.8 to 36.0)	33.4 (31.4 to 35.3)	0.51 (−2.4 to 3.4)	0.05	.98	0.75 (0.69 to 0.80)
SF-12 mental health^e^,^f	Pre	44.3 (42.9 to 45.7)	42.5 (41.2 to 43.8)	2.6 (0.81 to 4.4)	0.46	.003	0.53 (0.44 to 0.63)
SF-12 mental health^e^,^f	Post	44.5 (43.3 to 45.7)	45.1 (43.8 to 46.3)	2.6 (0.81 to 4.4)	0.46	.003	0.03 (0.01 to 0.57)

Abbreviations: De Jong, De Jong Giervald Loneliness Scale; GAD-7, Generalized Anxiety Disorder scale; ICC, intraclass correlation coefficient; LSNS, Lubben Social Network Scale; PHQ-8, Personal Health Questionnaire for Depression; SF-12, Short Form Health Survey Questionnaire; UCLA, UCLA Loneliness Scale.

^{^a}

Cohen d for the group difference at the postassessment stage.

^{^b}

P value for the interaction of group × days, the substantive effect of interest from mixed-effect regressions.

^{^c}

ICC and random variance approached 0 in all instances except for the mental health scale of the SF-12 for the caller’s cluster. In these instances, we did not include point estimates in the table.

^{^d}

The cells report the observed proportion meeting the clinical cutoff in each of the 4 cells, associated 95% CIs, and proportion differences. The P values and the ICCs are obtained from the mixed logistic regressions.

^{^e}

The direction of the interaction effect for SF-12 mental health scale concerned differences in within-group change rather than group differences at the postassessment stage. It is those differences that are presented in the group difference at the postassessment column of this table.

^{^f}

The ICC values given in the top concern participant clusters and the values of ICC below it concern caller clusters.