Data sources
We used the Web of Science Core Collection (WoS, by Clarivate Analytics) to collect all studies that cited the index study. WoS is commonly used for bibliometric analyses,14and we chose this database over alternatives such as Scopus and Google Scholar because of the availability of detailed citation metadata such as research areas, article type, funding agencies, and countries of origin. We conducted a search in June 2019 and then an update in July 2020 covering the period from the publication of the index study through to the end of 2019. The citation information for every article was collected into EndNote (by Clarivate Analytics), which was used to retrieve full text records. The remaining full text records were retrieved manually. We examined all the retrieved full text articles to ensure that the index study was indeed cited. Metadata collected from WoS were collected and managed using Microsoft Excel (by Microsoft).