Lower copays, use of mail order can reduce disparities in hypertension, medication adherence

An observational study using electronic medical record data of more than 44,000 patients recently diagnosed with high blood pressure in Kaiser Permanente Northern California identified important differences in medicine-taking behaviors among racial and ethnic groups. Lower copayments and the use of mail-order pharmacy increased refills of blood-pressure medicine, and these factors were associated with reduced disparities.

“We identified patients at the time they initiated therapy and followed their health services use for 1 year,” lead author Alyce C. Adams, PhD, research scientist with the Kaiser Permanente Division of Research, told Formulary.

“In an integrated healthcare setting with comprehensive hypertension care services, we found that reduced copays and participation in mail-order pharmacy, which included a reduced copayment for some members, were associated with reduced gaps in medication adherence by race and ethnicity,” she said.  

Primary nonadherence, or failing to pick up a prescribed medication, was rare. More than one-third of patients failed to refill a medication within 90 days of the first fill, and this varied considerably by race. After adjusting for other variables, black (43.6%), Asian (38.8%), and Latino (41.6%) patients all had significantly higher odds of early nonpersistence than white (31%) patients.

Nonadherent patients were defined as those with gaps in medication refills for more than 20% of the days in the measurement period, or having medication available less than 80% of the time. Of the nonadherent patients studied, 28% were black, 26.9% were Latino, 20.3% were Asian, and 16.7% were white. The impact of race and ethnicity on nonadherence was significantly reduced when the authors accounted for differences in copayment and enrollment in mail-order pharmacy; both mail-order pharmacy enrollment and lower copayments were significantly associated with a lower likelihood of being nonadherent.

“Previous studies have identified racial and ethnic differences in medication adherence, but few provide any guidance to healthcare systems in how to address these differences,” according to Adams. “We set out to identify modifiable factors that can be used in interventions to address disparities in hypertension.”

CARDIOVASCULAR DISPARITIES

Medication nonadherence is a critical challenge in efforts to improve cardiovascular disparities, according to Adams. “This study suggests that these disparities are not unalterable and that copay reduction and mail order pharmacy are potential tools in disparities intervention efforts,” she said.

However, the context in which these interventions are employed is also important, Adams said. “Kaiser Permanente Northern California has had tremendous success in treating hypertension over the past decade with 87% of its members with hypertension being in control.

 “These findings suggest that health system interventions that ease access to medications may be important tools in efforts to reduce persistent disparities in medication adherence among patients newly treated for hypertension,” Adams added.