Lipid-lowering Therapy Utilization, Adherence, and Outcomes Among Adults With and at-Risk for Atherosclerotic Cardiovascular Disease in an Integrated Healthcare Delivery System in Southern California.

Despite their safety and effectiveness, lipid-lowering therapy (LLT) remains underutilized among adults with and at-risk for atherosclerotic cardiovascular disease (ASCVD) in terms of prescriber-guideline concordance and patient adherence. We examined LLT use, adherence, and outcomes among primary and secondary prevention populations. Adults ≥21 years of age in Kaiser Permanente Southern California with a history of ASCVD or intermediate (≥7.5% to <20%) or high (≥20%) 10-year ASCVD risk between January 1, 2015 and March 31, 2021 were included. LLT use was described within subgroups including baseline risk. LLT adherence trajectories were determined using group-based trajectory modeling over 12 months. Hazard ratios (HR) were calculated for the association of adherence with ASCVD outcomes, identified starting in month 13 until death, disenrollment, or March 31, 2023. Among 730,941 adults (mean age 63 years; 42.1% female; 33.7% Hispanic and 41.3% non-Hispanic White), 30.3% and 47.4%, respectively, were intermediate- and high-risk for ASCVD, and 22.3% had ASCVD. Overall, 21% were not taking LLT, including 24% with ASCVD, and 32.4% of LLT users discontinued treatment at 12 months. High, intermediate, and low LLT adherence trajectories accounted for 64.1%, 24.3%, and 11.6% of the population, respectively. Adherence to LLT was associated with risk of ASCVD regardless of baseline statin intensity: adjusted HR of composite ASCVD associated with low and intermediate adherence was 1.20 (95% CI 1.16, 1.23) and 1.13 (95% CI 1.11, 1.15), respectively compared to patients with high adherence. LLT was underutilized in this contemporary population within an integrated health system in Southern California. In conclusion, addressing clinical inertia, enhancing medication management and lipid testing, and assessing clinical quality and metrics around guideline-appropriate care are critical given the persistent burden of CVD.