Comparison 2. Main analysis: patient‐reported or observer‐reported outcomes.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Patient‐reported binary outcomes	31	4046	Risk Ratio (M‐H, Random, 95% CI)	0.93 [0.86, 1.00]
2 Observer‐reported binary outcomes	13	1995	Risk Ratio (M‐H, Random, 95% CI)	0.93 [0.85, 1.02]
3 Patient‐reported continuous outcomes	109	8000	Std. Mean Difference (IV, Random, 95% CI)	‐0.26 [‐0.32, ‐0.19]
4 Observer‐reported continuous outcomes	49	2513	Std. Mean Difference (IV, Random, 95% CI)	‐0.13 [‐0.24, ‐0.02]