Extract the last test done by a patient in days and how long ago

This determines the last test done by that patient and the time between now and that last test in days

SurveilLastToNow(dataframe, HospNum_Id, Endo_ResultPerformed)

Arguments

dataframe	dataframe
HospNum_Id	Patient ID
Endo_ResultPerformed	Date of the Endoscopy

Examples

bb<-SurveilLastToNow(Myendo,'HospitalNumber',
'Dateofprocedure')