Comparison 1. Effects of school‐based asthma interventions vs usual care.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Exacerbations leading to hospitalisation	6	1873	Std. Mean Difference (Random, 95% CI)	‐0.19 [‐0.35, ‐0.04]
2 Exacerbations leading to emergency department (ED) visits	13	3883	Odds Ratio (Random, 95% CI)	0.70 [0.53, 0.92]
3 Absence from school	10	4609	Std. Mean Difference (Random, 95% CI)	‐0.07 [‐0.22, 0.08]
4 Days of restricted activity	3	1852	Std. Mean Difference (Random, 95% CI)	‐0.30 [‐0.41, ‐0.18]
5 Unplanned visit to hospital or GP due to asthma symptoms	5	3490	Odds Ratio (Random, 95% CI)	0.74 [0.60, 0.90]
6 Experience of daytime and night‐time symptoms ‐ daytime symptoms	5	1065	Std. Mean Difference (Random, 95% CI)	‐0.15 [‐0.33, 0.02]
7 Experience of daytime and night‐time symptoms ‐ night‐time symptoms	4	459	Std. Mean Difference (Random, 95% CI)	‐0.18 [‐0.52, 0.15]
8 Use of reliever therapies, e.g. beta₂‐agonists	2	437	Odds Ratio (Random, 95% CI)	0.52 [0.15, 1.81]
9 Corticosteroid dosage and/or use of add‐on therapies (usage of)	3	614	Odds Ratio (Random, 95% CI)	1.25 [0.88, 1.77]
10 Corticosteroid dosage and/or use of add‐on therapies (appropriate usage of)	2		Std. Mean Difference (Random, 95% CI)	Totals not selected
11 Health‐related quality of life (SMD)	7	2587	Std. Mean Difference (Random, 95% CI)	0.27 [0.18, 0.36]
12 Health‐related quality of life (MD)	8	2950	Mean Difference (IV, Random, 95% CI)	0.35 [0.06, 0.64]
13 Withdrawal from the study	13	3442	Odds Ratio (Random, 95% CI)	1.14 [0.92, 1.43]