Quantifying adherence to pharmacotherapy using healthcare utilization data, adapted from prior summaries[18, 25]. Adherence is a general term describing medication taking behaviour and is examined using healthcare utilization data by measurement of compliance and persistence in the observation period. The proportion of days covered (PDC) is also commonly referred to as the medication possession ratio (MPR). We recommend PDC as the standard terminology and measurement of compliance.
t0=start of observation period
t1=end of observation period