Extracts the first test only per patient

Extracts the first test only per patient

SurveilFirstTest(dataframe, HospNum_Id, Endo_ResultPerformed)

Arguments

dataframe

dataframe
HospNum_Id

Patient ID
Endo_ResultPerformed

Date of the Endoscopy

Examples

dd<-SurveilFirstTest(Myendo,'HospitalNumber',
'Dateofprocedure')