Non-equivalency studies (success is an effect size with a large positive magnitude)  • Comparison of a supervision strategya aloneb versus a (no-intervention) control group  • Comparison of one supervision strategya aloneb versus a different supervision strategya aloneb (e.g., “audit with in-person feedback” versus “audit with written feedback”)  • Comparison of a supervision strategya combined with a specific group of other strategy componentsc versus that same specific group of other strategy componentsc (e.g., “routine supervision plus training” versus “training”)  • Comparison of one supervision strategya combined with a specific group of other strategy componentsc versus a different supervision strategya combined with that same specific group of other strategy componentsc (e.g., “routine supervision plus training” versus “peer review plus training”) Equivalency studies (success is an effect size close to zero)  • Comparison in a supervision-related study of a strategy versus a “gold standard” comparison groupd

^aAny of the six supervision strategies listed in the top part of Box 1

^bThat is, not combined with other strategy components listed in the bottom part of Box 1

^cOne or more of the 11 other strategy components in the bottom part of Box 1

^dOnly one equivalency study was included in the analysis. In that study, at baseline, lay HCPs in two study arms received routine supervision plus reminders about making home visits; during the intervention period, the gold standard control arm continued receiving both supervision and reminders, and the intervention arm received only the reminders