Comparison 1. Mepolizumab (SC) versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1.1 Rate of exacerbations requiring systemic corticosteroids	2	936	Rate Ratio (IV, Random, 95% CI)	0.45 [0.36, 0.55]
1.1.1 Eosinophilic	2	936	Rate Ratio (IV, Random, 95% CI)	0.45 [0.36, 0.55]
1.2 At least one clinically significant exacerbation	1	295	Odds Ratio (M‐H, Random, 95% CI)	0.59 [0.37, 0.93]
1.2.1 Eosinophilic	1	295	Odds Ratio (M‐H, Random, 95% CI)	0.59 [0.37, 0.93]
1.3 Rate of exacerbations requiring admission	2	936	Rate Ratio (IV, Random, 95% CI)	0.31 [0.13, 0.73]
1.3.1 Eosinophilic	2	936	Rate Ratio (IV, Random, 95% CI)	0.31 [0.13, 0.73]
1.4 Rate of exacerbations requiring ED treatment or admission	2	936	Rate Ratio (IV, Random, 95% CI)	0.36 [0.20, 0.66]
1.4.1 Eosinophilic	2	936	Rate Ratio (IV, Random, 95% CI)	0.36 [0.20, 0.66]
1.5 Health‐related quality of life (ACQ)	3	1231	Mean Difference (IV, Random, 95% CI)	‐0.38 [‐0.50, ‐0.26]
1.5.1 Eosinophilic	3	1231	Mean Difference (IV, Random, 95% CI)	‐0.38 [‐0.50, ‐0.26]
1.6 Health‐related quality of life (SGRQ)	3	1231	Mean Difference (IV, Random, 95% CI)	‐6.37 [‐8.76, ‐3.98]
1.6.1 Eosinophilic	3	1231	Mean Difference (IV, Random, 95% CI)	‐6.37 [‐8.76, ‐3.98]
1.7 Pre‐bronchodilator FEV 1 (litres)	3	1231	Mean Difference (IV, Random, 95% CI)	0.09 [0.05, 0.14]
1.7.1 Eosinophilic	3	1231	Mean Difference (IV, Random, 95% CI)	0.09 [0.05, 0.14]
1.8 Serious adverse events	3	1231	Risk Ratio (M‐H, Random, 95% CI)	0.68 [0.46, 1.01]
1.8.1 Eosinophilic	3	1231	Risk Ratio (M‐H, Random, 95% CI)	0.68 [0.46, 1.01]
1.9 Adverse events leading to discontinuation	3	1231	Risk Ratio (M‐H, Random, 95% CI)	0.60 [0.19, 1.85]
1.9.1 Eosinophilic	3	1231	Risk Ratio (M‐H, Random, 95% CI)	0.60 [0.19, 1.85]