Table 3.

Mean Effect Sizes and Moderator Analyses (k = 38)

Parameter	k	Effect Size (g)	95% CI	P	Heterogeneity
Mean effect size
Pain severity*	38	0.34	0.23 to 0.46	< .001	I2 = 60.1, P < .001
Pain interference	4	0.40	0.21 to 0.60	< .001	I2 = 0.001, P = .74
Categorical moderators (pain severity)
Intervention type†
Skills based	18	0.45	0.21 to 0.69	.22
Educational	19	0.29	0.19 to 0.39
Pain as study outcome
Primary	32	0.37	0.24 to 0.50	.26
Secondary	6	0.24	0.06 to 0.42
Presence of pain required for eligibility
No	14	0.33	0.06 to 0.59	.94
Yes	24	0.34	0.22 to 0.45
Delivery setting
Clinic only	24	0.25	0.10 to 0.40	.08
Home	8	0.43	0.29 to 0.58
Continuous moderators (pain severity)
No. of treatment sessions	38	B = 0.002		.76
Percentage of women to men participants	35	B = 0.001		.77
Percentage of minority participants (US studies only)	19	B = 0.001		.50

^*All studies fall within 2 standard deviations of the mean effect size.

^†Goodwin et al³⁴ was removed for this analysis because it was the only intervention primarily based on social support.