An S4 class for a cohort exit based on continuous exposure persistence.

Specify a concept set that contains one or more drugs. A drug era will be derived from all drug exposure events for any of the drugs within the specified concept set, using the specified persistence window as a maximum allowable gap in days between successive exposure events and adding a specified surveillance window to the final exposure event. If no exposure event end date is provided, then an exposure event end date is inferred to be event start date + days supply in cases when days supply is available or event start date + 1 day otherwise. This event persistence assures that the cohort end date will be no greater than the drug era end date.

Slots

conceptSet

the concept set of the drug exposure used to identify the exit

persistenceWindow

allow for a maximum of days between exposure records when inferring the era of persistence exposure

surveillanceWindow

add days to the end of the era of persistence exposure as an additional period of surveillance prior to cohort exit

daysSupplyOverride

force drug exposure days supply to a set number of days

count

an integer specifying the number of occurrences for a criteria