Comparison 10. Effects of school‐based asthma interventions vs usual care subgrouped by number of consistent conditions (use of theory, parental involvement, not in own time).

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 No conditions	0		Odds Ratio (Random, 95% CI)	0.0 [0.0, 0.0]
1.2 One condition	3		Odds Ratio (Random, 95% CI)	0.56 [0.33, 0.97]
1.3 Two conditions	7		Odds Ratio (Random, 95% CI)	0.67 [0.49, 0.94]
1.4 Three conditions	3		Odds Ratio (Random, 95% CI)	1.48 [0.65, 3.40]
2 Absence from school	10		Std. Mean Difference (Random, 95% CI)	‐0.07 [‐0.22, 0.08]
2.1 No conditions	0		Std. Mean Difference (Random, 95% CI)	0.0 [0.0, 0.0]
2.2 One condition	3		Std. Mean Difference (Random, 95% CI)	0.02 [‐0.08, 0.11]
2.3 Two conditions	4		Std. Mean Difference (Random, 95% CI)	‐0.16 [‐0.43, 0.11]
2.4 Three conditions	3		Std. Mean Difference (Random, 95% CI)	0.07 [‐0.22, 0.37]
3 Withdrawal from the study	13		Odds Ratio (Random, 95% CI)	1.14 [0.92, 1.43]
3.1 No conditions	0		Odds Ratio (Random, 95% CI)	0.0 [0.0, 0.0]
3.2 One condition	1		Odds Ratio (Random, 95% CI)	0.61 [0.30, 1.26]
3.3 Two conditions	7		Odds Ratio (Random, 95% CI)	1.22 [0.83, 1.80]
3.4 Three conditions	5		Odds Ratio (Random, 95% CI)	1.22 [0.91, 1.64]