Plain language summary Summary of findings Background Description of the condition Description of the intervention How the intervention might work Why it is important to do this review Objectives Methods Criteria for considering studies for this review Search methods for identification of studies Data collection and analysis Results Description of studies Risk of bias in included studies Effects of interventions Discussion Summary of main results Overall completeness and applicability of evidence Quality of the evidence Potential biases in the review process Agreements and disagreements with other studies or reviews Authors' conclusions Acknowledgements Data and analyses Contributions of authors Contributions of editorial team Declarations of interest Sources of support Internal sources External sources Differences between protocol and review Characteristics of studies Characteristics of included studies [ordered by study ID] Characteristics of excluded studies [ordered by study ID] Characteristics of ongoing studies [ordered by study ID] Risk of bias Appendices Appendix 1. Database search strategy Appendix 2. Analysis Codes Appendix 3. Model fit parameters Appendix 4. Node-splitting results for severe exacerbations Appendix 5. Node-splitting results for moderate to severe exacerbations for grouped treatments Appendix 6. Node-splitting results for CFB in ACQ score at 3 months Appendix 7. Node-splitting results for CFB in ACQ score at 6 months. Appendix 8. Node-splitting results for CFB in ACQ scores at 12 months Appendix 9. Node-splitting results for CFB in AQLQ scores at 6 months Appendix 10. Node-splitting results for ACQ Response at 6 months Appendix 11. Node-splitting results for asthma-related SAEs Appendix 12. Node-splitting results for all-cause SAEs