a Cochrane databases include the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews
b Other sources include prior reports, reference lists of relevant articles, systematic reviews, etc.
c Includes 10 trials that were identified in the 2018 report search.
d Publications may be included or excluded for multiple interventions
e Studies checked for inclusion
f One of the publications identified for update report was a followup study to a trial included in the previous report, therefore this study is not counted in the number of included trials but is counted under total publications.