Abstract 4198: Short-term Clinical Consequences of Nonadherence in Patients with Hypertension and Multiple Risk Factors
Objective: To quantify the short-term clinical consequences of nonadherence to concomitant antihypertensive (AH) and lipid-lowering (LL) therapy among primary prevention patients with hypertension and multiple risk factors.
Design and Methods: A microsimulation model was developed to compare cardiovascular event rates over 3 years under 3 treatment scenarios: no treatment, typical adherence, and ideal adherence. Population characteristics were modeled on the ASCOT-LLA study. The “no treatment” scenario represented a natural-history model, with CHD (non-fatal MI, angina pectoris, or CHD death) and stroke probabilities determined by Framingham Heart Study risk equations. “Ideal adherence” incorporated adherence levels and risk reduction from ASCOT-LLA. “Typical adherence” reflected time-dependent annual transitions among three adherence categories based on data from a U.S. Medicaid population: non-adherent (≤ 20% days covered), partially adherent (20 − 80%), or fully adherent (≥ 80%). This scenario assumed a linear association between adherence and risk reduction.
Results: In the “no treatment” scenario, event rates per 1,000 patient-years were 15.1 and 8.1 for CHD and stroke, respectively. The typical adherence scenario yielded fewer CHD events (relative risk 0.68 [95% CI 0.63– 0.72]) and stroke events (0.68 [0.62– 0.74]). Full adherence to both treatments would yield greater reductions in CHD (0.40 [0.37– 0.43]) and stroke (0.51 [0.47– 0.57]). Increasing adherence from typical to ideal levels would prevent an incremental 1200 CHD events and 400 stroke events per 100,000 treated patients over a 3-year period.
Conclusions: With typical AH and LL adherence, hypertensive primary prevention patients with multiple risk factors can be expected to receive approximately 57% of the potential protection from CHD and stroke events associated with full adherence.