CREATE INDEX ON :ClinicalTrial(NCTId);

call apoc.load.json('https://ClinicalTrials.gov/api/query/study_fields?expr=covid&fields=NCTId,Condition,LeadSponsorName,LocationFacility,BriefTitle,InterventionName,CollaboratorName,LocationCity,OverallStatus,PrimaryOutcomeMeasure,StartDate,LocationState,StudyType,StudyFirstSubmitDate,PrimaryCompletionDate,LocationCountry&fmt=json&max_rnk=1000') yield value
with value.StudyFieldsResponse.StudyFields as coll unwind coll as study_metadata
with study_metadata
merge (ct:ClinicalTrial{NCTId:study_metadata.NCTId,data_source:'clinicaltrials.gov'})
set ct += study_metadata
set ct.url = [nctid in study_metadata.NCTId | 'https://clinicaltrials.gov/ct2/show/' + nctid]
return ct;