Pharmacist Intervention Among Patients With Comorbidities

Philadelphia, PA—A brief pharmacist telephone intervention resulted in significantly better proportion of days covered (PDCs) during the 6 months following the intervention among a group of nonadherent patients with comorbid hypertension and diabetes enrolled in a Texas-based Medicare Advantage plan. However, improving adherence to clinically meaningful values may require more than a brief pharmacist phone call, according to study results presented at the ISPOR meeting during a poster session titled Impact of a Pharmacist Telephone Intervention on Medication Adherence Among Hypertensive Patients with Diabetes in a Medicare Advantage Plan.

Patients with comorbid hypertension and diabetes face greater risk of developing macrovascular and microvascular complication of diabetes. Controlling high blood pressure can help reduce these complications. The American Diabetes Association guidelines recommend angiotensin-converting enzyme (ACE) inhibitors/angiotensin receptor blockers (ARBs) for patients with both conditions. Furthermore, the benefits of these medications in reducing macrovascular and microvascular complications of diabetes have been well-documented. Yet, poor adherence remains an important barrier to achieving full effectiveness and optimal outcomes among this patient population.

To examine the effect of a brief pharmacist intervention on adherence to ACE inhibitors/ARBs among nonadherent patients with hypertension and diabetes, the researchers conducted a retrospective cohort study of 131 patients continuously enrolled in the Medicare prescription drug plan in Texas from January 2013 to June 2014. The health plan medical claims data was used to identify patients who had a diagnosis of hypertension and diabetes based on ICD-9 codes and at least 2 prescription fills for ACE inhibitors or ARBs between January 2013 and October 2013. Patients who failed to refill their medication for >1 day, and had PDC <80% were considered nonadherent and received a telephone call from a pharmacist. 

The majority of the patients enrolled were female (54%), and the mean age of the study cohort was 71 years. More than half of the patients (58%) received care from a primary care physician, while 41% of patients were under a specialist’s care. Excluding the ACE inhibitors and ARBs, the number of medications among the study cohort was 12.76, and the baseline PDC was 0.67.

Intervention was a significant predictor of better adherence on the linear regression model after adjusting for other baseline covariates (ß=0.318; P<.001). Mean post-intervention PDC for the intervention group (n=66) was 0.58 (standard deviation [SD]±0.26) and 0.29 (SD±0.17) for the control group (n=65). However, the overall PDC rates in both the intervention and control groups remained lower than the recommended 80%.

“Incorporating motivational interviewing techniques with follow-up calls to address adherence barriers may be more influential in forming a sustainable behavioral change and further enhance adherence,” the investigators concluded.—Eileen Koutnik-Fotopoulos