Use of pharmacy dispensing data to measure adherence and identify nonadherence with oral hypoglycemic agents

Purpose: A framework for calculation of adherence for oral hypoglycemic agents (OHAs) based on data from healthinsurance claims is available. Pharmacy dispensing data aid identification of nonadherent patients in pharmacy practices. However, use of these data for calculation of OHA adherence requires additional methodological categories. We examined the impact of different methodological choices on estimation of OHA adherence using pharmacy dispensing data. Methods: Four methodological categories were added to the framework available to be used for adherence calculation with pharmacy dispensing data. Three adherence measures were defined to supply pharmacists with significant information on OHA use of their patients: (i) percentage of days covered by use periods of dispensed medication (PDC), (ii) mean rate of adherent patients with a PDC ≥80 % (MRAP80), and (iii) mean number of nonadherent patients (MNNP80) per pharmacy with a PDC