Comparison 2. Effects of school‐based asthma interventions vs usual care subgrouped by school type.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Exacerbations leading to emergency department (ED) visits	13		Odds Ratio (Random, 95% CI)	0.70 [0.53, 0.92]
1.1 Secondary/high school	2		Odds Ratio (Random, 95% CI)	0.61 [0.40, 0.92]
1.2 Primary/elementary school	11		Odds Ratio (Random, 95% CI)	0.73 [0.52, 1.02]
2 Absence from school	10		Std. Mean Difference (Random, 95% CI)	‐0.07 [‐0.22, 0.08]
2.1 Secondary/high school	1		Std. Mean Difference (Random, 95% CI)	‐0.38 [‐0.62, ‐0.15]
2.2 Primary/elementary school	7		Std. Mean Difference (Random, 95% CI)	‐0.05 [‐0.27, 0.16]
2.3 Primary/elementary and middle schools	1		Std. Mean Difference (Random, 95% CI)	0.02 [‐0.08, 0.12]
2.4 Middle school	1		Std. Mean Difference (Random, 95% CI)	0.08 [‐0.31, 0.48]
3 Withdrawal from the study	13		Odds Ratio (Random, 95% CI)	1.14 [0.92, 1.43]
3.1 Secondary/high school	3		Odds Ratio (Random, 95% CI)	1.25 [0.76, 2.06]
3.2 Primary/elementary school	8		Odds Ratio (Random, 95% CI)	1.22 [0.94, 1.59]
3.3 Middle school	2		Odds Ratio (Random, 95% CI)	0.59 [0.29, 1.20]