PCPs Overestimate Medication Adherence Among Medicare Beneficiaries

Primary care physicians correctly estimate medication adherence of their Medicare patients only half of the time and usually overestimate adherence rates, according to a new study.

A new survey of primary care physicians (PCPs) contracted with a Texas Medicare Advantage Part D (MA-PD) plan found that PCPs correctly estimate medication adherence only about half the time and appear to be more likely to overestimate rather than underestimate medication adherence rates. These findings were in line with earlier published research.

The ability of physicians to recognize medication nonadherence in their patients is an important issue given the evidence that medication nonadherence is associated with adverse health outcomes and higher costs of care. Medication nonadherence is especially a concern with the Medicare population, in which patients take an average of six to eight medications.

The study, published in the Journal of Managed Care & Specialty Pharmacy, found that while most PCPs believe that more than 75% of their patients are adherent to renin-angiotensin system (RAS) antagonists and diabetes agents, only 50% to 75% are adherent to statins.

Amanda Winters, PharmD, of Cigna-HealthSpring, in Houston, TX, and colleagues assessed 226 PCPs’ perceptions of patient medication adherence for each of the CMS MA-PD star medication classes (including statins, oral antidiabetes drugs [OADs], and RAS antagonists). The study’s goal was to compare the PCPs’ perceptions of the percentage of adherent patients with the actual percentage of adherent patients, calculated from pharmacy claims.

The survey also asked PCPs what financial category patients were in and whether they received samples. Use of medication samples is an important item to quantify because samples are not captured in pharmacy claims and so are not reflected in PCD calculations. In this survey, less than 25% of patients were said to use samples. PCPs’ survey responses were compared with pharmacy claims data on the proportion of days covered for all 3 medication categories in each PCP’s patient population.

The survey used in the study had a very high response rate (78%), achieved without the use of direct incentives. The study authors noted that the PCPs they surveyed are highly motivated to improve patient medication adherence.

“Physicians cannot take actions to correct medication adherence if they are unaware that the problem exists,” the study’s authors noted.

They concluded that patient education efforts may be an important step in overcoming barriers to statin adherence, and they add that pharmacists are well equipped to assist in feedback regarding medication adherence rates, implementing initiatives for adherence improvement, and educating patients on the necessity for medication.