A light wrapper around impute_duration.
decision_7(data, decision = "a")a data frame
one of the following strings:
Leave missing durations as-is (implicitly drop the prescription)
Use mean prescription duration for that drug, for that individual
Use mean prescription duration for that drug, for the population
Use individual mean duration; if not available use population mean
Other decision functions:
decision_10(),
decision_1(),
decision_2(),
decision_3(),
decision_4(),
decision_5(),
decision_6(),
decision_8(),
decision_9(),
drug_prep()