Poor medication adherence has been increasingly recognized as a major public health issue and a priority for health care reform. Primary medication nonadherence (PMN) is a subset of this broader subject and occurs when a new medication is prescribed for a patient, but the patient does not obtain the medication, or an appropriate alternative, within an acceptable period of time after it was prescribed. It is increasingly evident that the public health problem of PMN is widespread. However, the lack of standardized definitions and measures inhibits the ability to establish the true incidence of this problem or to track changes in PMN rates over time. Given the limitations of current measures, the Pharmacy Quality Alliance (PQA) convened an expert working group to set parameters for a new industry measure. That new measure, which links electronic prescribing and pharmacy dispensing databases and was developed and approved by the PQA, is described here. PMN literature from 1990 to June 2015 is also reviewed, and existing PMN measures are summarized.
Disclosures: No funding was received for this article, and the authors declare no conflicts of interest. The views expressed in this article are those of the authors alone and do not necessarily reflect those of their respective employers. Adams has received grant support from Pfizer for adherence research. Adams and Stolpe were equally involved in all aspects of study design, data collection and interpretation, and manuscript preparation.