Data Sources and Literature Search Strategy
The meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and registered in the Prospective Register of Systematic Reviews (PROSPERO ID CRD42021236232).11 PubMed, Embase and Web of Science were searched from inception to February 1, 2021 using the following Medical Subject Heading (MeSH) terms, keywords and word variants: “insulin dependent” or “type 1 diabetes” and “asthma”. Reference lists of the electronically identified articles were manually searched.