*2.1. Data Sources and Literature Search*

Relevant publications indexed in electronic databases (MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Web of Science) between database inception and 1 February 2021 were searched. The keywords "atopic dermatitis" and "Janus kinase inhibitor" and their synonyms and derivatives were used for the search. Details of the search strategies are described in Table S1 in the Supplementary Materials. No language restriction was applied. To identify unpublished or ongoing trials, the trial registries of the US National Institutes of Health (https://clinicaltrials.gov/ accessed on 2 February 2021), International Clinical Trials Registry Platform (https://www.who.int/ictrp/en/ accessed on 2 February 2021), and European Union Drug Regulating Authorities Clinical Trials Database (https://eudract.ema.europa.eu/ accessed on 3 February 2021) were searched. The bibliographies of available review articles and meta-analyses were also examined to find additional candidate studies. The literature search was performed with the assistance of a librarian (L.Y. Chen) at Hualien Tzu Chi Hospital.
