Supplementary file 3 – list of variables in the dataset

Variable	Notes	
NCT.ID*	The ID of each study assigned by ClinicalTrials.gov	
Title*	The title of the study on ClinicalTrials.gov	
Recruitment*	Recruitment status of the study at the time of the search	
Study.Results*	Variable indicating if the study has uploaded summary results to ClinicalTrials.gov	
Conditions*	Condition studied by the trial	
Interventions*	Intervention studied in the trial	
Sponsors*	Sponsor of the trial	
Gender*	Gender of the participants in the trial	
Age.Group*	Age groups of the participants in the trial	
Phases*	Phase of the trial	
Enrolment*	Enrolment in the trial	
Funded.By*	Funder of the trial	
Study.Types*	Type of study (e.g. ‘interventional’)	
Study.Designs*	Design variable of the study (e.g. randomised, blinded etc)	
Other.IDs*	Other identifiers for the trial	
First.Received*	Date registry entry first received by ClinicalTrials.gov	
Start.Date*	Start date of the trial	
Completion.Date*	Date trial completed 	
Last.Updated*	Date record for trial last updated on ClinicalTrials.gov	
Last.Verified*	Date record for trial last verified	
Acronym*	Acronym of the trial	
Primary.Completion.Date*	Date trial completed (last visit of last patient)	
Outcome.Measure*	Outcome measure used in the trial	
URL*	ClinicalTrials.gov URL for the record	
Study.Location **	ClinicalTrials.gov location for the study (location of participating sites).  These data was obtained by webscraping the website with a script to record the sites of the individual studies.  	
Drug	Is the trial of a drug? 	
FDA_app	Were all the drugs in the trial approved by the FDA at the time of the search? (1 = yes, 0 = no, NA = not applicable)	
Number_ints	Number of interventions in the trial	
Brand_name_in_trial	Were all drugs in the trial identified by brand names and were all of these brand names approved by the FDA at the time of the search (1 = yes, 0 = no, NA = not applicable)	
* These variables can be downloaded directly from the ClinicalTrials.gov website in a spreadsheet format, and the definitions therefore follow the ones used by ClinicalTrials.gov.
** This variable was obtained with the R script