Cost of heart failure drugs impacts medication adherence

Key Points

In a new study published ahead of print on the Mayo Clinic Proceedings website, researchers demonstrated that the cost of medications was a factor influencing the proportion of patients with heart failure who had poor medication adherence to beta-blockers, angiotensin converting-enzyme inhibitors (ACEIs) or receptor blockers (ARBs), and statins.

To evaluate medication use and adherence in a community-based heart failure cohort, researchers used electronic medical records to prospectively identify patients with heart failure from a population of Olmsted County, Minn., residents. Patients provided authorization to obtain pharmacy records from all pharmacies where they had refilled medications in the past 2 years, and responded to questionnaires to assess global medication adherence and the effect of the cost of medication on adherence. Medication adherence was determined for each medication class, and was calculated as the proportion of days covered (PDC). Poor adherence was defined as a PDC <80%.

Ultimately, researchers studied 245 patients with New York Heart Association (NYHA) class I to IV heart failure. The proportion of patients with heart failure who had a PDC <80% to beta-blockers, ACEIs/ARBs, and statins was 19%, 19%, and 13%, respectively.

Researchers also found that those with poor adherence expressed more cost-related medication issues. They highlighted statin use noting, "those who adhered poorly to statin therapy more frequently reported stopping a prescription because of cost than those with good adherence (46% vs 6%; P<.001), skipping doses to save money (23% vs 3%; P=.03), and not filling a new prescription because of cost (46% vs 6%; P<.001)."

SOURCES

Dunlay SM, Eveleth JM, Shah ND, McNallan SM, Roger VL. Medication adherence among community-dwelling patients with heart failure. Mayo Clin Proc. 2011 Mar 9. [Epub ahead of print].

American Heart Association. Heart Disease and Stroke Statistics – 2009 Update. Dallas, Texas: American Heart Association; 2009. Available at: http://www.americanheart.org/presenter.jhtml?identifier=3037327/. Accessed March 31, 2011.