Relationship Between Adherence to Antihypertensive Medication Regimen and Out-of-Pocket Costs Among People Aged 35 to 64 With Employer-Sponsored Health Insurance

Madeleine M. Baker-Goering, PhD; Kakoli Roy, PhD; David H. Howard, PhD


Prev Chronic Dis. 2019;16(3):e32 

In This Article


In 2014, 22% of adults aged 35 to 64 (N = 2,897,548) were diagnosed with hypertension (Table 1). Among the 27% (N = 3,462,582) of adults who filled prescriptions for antihypertensive medications, 41% (N = 1,428,298) of those who filled a prescription were nonadherent to their antihypertensive medication regimen. Nonadherence decreased with age and was higher for women than men and for people using branded medications than those using generic ones. Regionally, nonadherence was highest among people living in the South.

Patients filled an average of 13 monthly antihypertensive medication prescriptions during the calendar year and paid on average $5.78 out of pocket per 30-day supply and $76 annually. Total costs (patient and insurer) for antihypertensive medications were $17 per 30-day supply and $229 annually. People who used branded medications had the highest out-of-pocket costs ($13.60 per 30-day supply) and highest total costs ($40.73 per 30-day supply). Patients in health maintenance organizations had higher out-of-pocket costs that those in other types of insurance plans. Residents of rural areas also had higher out-of-pocket costs than those paid by those in urban areas, but they used less expensive medications.

About 90% of patients incurred out-of-pocket costs for medications, but 83% paid less than $10 per 30-day supply of antihypertensive medications. However, 30% of patients paid the full costs of their medications (approximately $41 in annual out-of-pocket costs for an average of 10 fills during the calendar year.).

We calculated the unadjusted and multivariate-adjusted odds ratios for the association between nonadherence and patient characteristics (Table 2). The likelihood of nonadherence increased as out-of-pocket costs increased (odds ratios, compared with those with no out-of-pocket costs, ranged from 1.04 for those paying less than $5, to 1.78 for those paying more than $50).

The likelihood of nonadherence was greatest among patients who used branded antihypertensive medications and those living in the South and was smallest among those with a hypertension diagnosis in 2014 and patients aged 55 to 64. When we restricted the sample to patients with a hypertension diagnosis as a sensitivity analysis, the associations were similar in magnitude and significance.