Exposure
Treatment with an OAC was checked against the prescription fulfillment
dates and the number of days of medication supplied for each fill.
Exposure to treatment was considered in all analyses. We consider that a
gap of less than 30 days between the end of a treatment period and a new
fill corresponded to continuous treatment. Patients were censored when
they discontinued a treatment or switched to another OAC or to another
dose level. Allowing a gap in treatment of up to 30 days is reasonable
because of the DOACs’ short half-life. Taking account of this
definition, the adherence rate over the 12-month assessment period was
at least 92% for all included patients. The patient’s OAC exposure and
censored status were updated every 30 days.