Antihypertensive Triple-Combination Therapy “Adherence” Differs with Definition

A study comparing adherence to single-pill antihypertensive triple-combination therapy with free triple-combination therapy and fixed-dose dual-combination therapy plus a third agent found different results depending on how loosely adherence was defined.

“Measuring adherence to multiple concurrent regimens is complicated and different adherence definitions can result in significant variations in adherence measures,” researchers wrote. “Future research evaluating clinical outcomes with various definitions is needed.”

Researchers looked at medication adherence rates for 10,836 patients prescribed triple-combination therapy for hypertension who were enrolled in a Medicare Advantage prescription drug plan. Participants were grouped according to their antihypertensive triple-combination therapy type: single-pill triple-combination therapy, free triple-combination therapy, or fixed-dose dual-combination therapy plus a third agent.

Medication adherence was defined in two different ways: a stricter definition that required all antihypertensive agents during follow-up and a more relaxed definition that simply required any antihypertensive agent during follow-up.

Under the stricter adherence requirements, researchers found fixed-dose dual-combination therapy plus a third agent was significantly associated with lower adherence compared with a single pill. Adherence with single-pill triple-combination therapy compared with free triple-combination therapy, meanwhile, was not significantly different.

Under looser requirements that counted any antihypertensive agent as fulfilling the definition of adherence, fixed-dose dual-combination therapy plus a third agent and free-combination therapy were significantly linked with better adherence compared with a single pill.

“Influential factors that significantly affected medication adherence,” researchers added, “included age, gender, language, some comorbidities, and a previous hospitalization history.”

—Jolynn Tumolo

Reference

Wang X, Chen H, Essien E, et al. Medication adherence to antihypertensive triple-combination therapy among patients enrolled in a Medicare Advantage plan. J Manag Care Spec Pharm. 2019;25(6):678-686.