Table 4.

Meta-regressive estimates of effect modification by various study design and intervention characteristics (coarse model). Intercept: estimated mean risk ratio when all listed covariates are set to 0. For binary covariates, estimates represent risk ratios for the increase in intervention effectiveness associated with a study’s having, versus not having, the covariate. For the percentage of male subjects, the estimate represents the risk ratio for the increase in intervention effectiveness associated with a 10-percentage-point increase in males. For the average age, the estimate represents the risk ratio for the increase in intervention effectiveness associated with a 5-year increase in average subject age.

Coefficient	Effect modification RR [95% CI]	p-value
Intercept	1.11 [0.66, 1.86]	0.66
Intervention had text	0.85 [0.68, 1.06]	0.12
Intervention had visuals	0.96 [0.81, 1.13]	0.57
Intervention had graphic content	1.10 [0.97, 1.24]	0.13
Intervention’s recommendation
No recommendation	Ref.	Ref.
“Reduce consumption”	1.00 [0.77, 1.31]	0.98
“Go vegetarian”	1.03 [0.78, 1.36]	0.81
“Go vegan”	1.31 [1.06, 1.62]	0.03
Mixed recommendation	0.99 [0.83, 1.19]	0.94
Intervention duration >5 min	1.03 [0.86, 1.24]	0.70
Follow-up length at least 7 days	0.81 [0.68, 0.97]	0.03
Percentage male subjects (10-pt increase)	1.00 [0.95, 1.06]	0.88
Average subject age (5-year increase)	1.04 [0.98, 1.10]	0.15

CI: confidence interval. p-values are for the effect modification coefficients themselves, not for the subset of studies having the listed characteristic.