Comparison 2. Primary outcome subgroup and sensitivity analyses.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
2.1 Subgrouped by age	8		Odds Ratio (IV, Fixed, 95% CI)	0.97 [0.76, 1.25]
2.1.1 Children	4		Odds Ratio (IV, Fixed, 95% CI)	1.07 [0.76, 1.49]
2.1.2 Adults	4		Odds Ratio (IV, Fixed, 95% CI)	0.87 [0.60, 1.26]
2.2 Subgrouped by time to treatment initiation	8		Odds Ratio (IV, Fixed, 95% CI)	0.97 [0.76, 1.25]
2.2.1 < 48 hours	5		Odds Ratio (IV, Fixed, 95% CI)	1.02 [0.77, 1.36]
2.2.2 ≥ 48 hours	3		Odds Ratio (IV, Fixed, 95% CI)	0.84 [0.51, 1.39]
2.3 Subgrouped by maintenance ICS dose	7		Odds Ratio (IV, Fixed, 95% CI)	0.96 [0.75, 1.24]
2.3.1 Low	2		Odds Ratio (IV, Fixed, 95% CI)	1.30 [0.83, 2.02]
2.3.2 Medium	3		Odds Ratio (IV, Fixed, 95% CI)	0.78 [0.52, 1.18]
2.3.3 High	2		Odds Ratio (IV, Fixed, 95% CI)	0.91 [0.58, 1.42]
2.4 Subgrouped by ICS dose during exacerbation	7		Odds Ratio (IV, Fixed, 95% CI)	0.96 [0.75, 1.24]
2.4.1 Low	1		Odds Ratio (IV, Fixed, 95% CI)	1.17 [0.57, 2.40]
2.4.2 High	6		Odds Ratio (IV, Fixed, 95% CI)	0.94 [0.72, 1.22]
2.5 Subgrouped by ICS fold increase	8		Odds Ratio (IV, Fixed, 95% CI)	0.97 [0.76, 1.25]
2.5.1 Double dose	6		Odds Ratio (IV, Fixed, 95% CI)	0.98 [0.72, 1.34]
2.5.2 More than double	2		Odds Ratio (IV, Fixed, 95% CI)	0.96 [0.63, 1.45]
2.6 Sensitivity analysis: parallel‐group studies only	6	1728	Odds Ratio (M‐H, Fixed, 95% CI)	0.96 [0.74, 1.24]
2.7 Sensitivity analysis: removing studies at overall high risk of bias	5		Odds Ratio (IV, Fixed, 95% CI)	0.93 [0.71, 1.21]
2.8 Sensitivity analysis: independently funded studies only	6		Odds Ratio (IV, Fixed, 95% CI)	0.93 [0.72, 1.21]