Treatment adherence patterns for patients with atherosclerotic cardiovascular disease: Patient and provider perspectives.

Background: Atherosclerotic cardiovascular disease (ASCVD) is a leading cause of mortality, affecting more than 500 million individuals globally. National guidelines recommend lipid-lowering therapies (LLTs) as first line agents for both primary and secondary prevention of ASCVD. However, under-prescribing of pharmacologic LLTs and sub-optimal medication adherence remain common problems.

Aim: This mixed-methods study aimed to identify patient and prescriber factors influencing adherence to LLTs.

Methods: Patients with an ASCVD diagnosis and treatment plan that included LLT were sampled from a large community health system serving seven states. A stratified random sample of 2500 patients was surveyed by mail, capturing barriers and facilitators to medication adherence using an adapted version of the Adherence Starts with Knowledge-12 (ASK-12) scale, achieving a 16.2 % response rate (406 patients). Twenty-three semi-structured interviews were conducted with a sample of patient survey respondents to further explore drivers of non-adherence. Eligible prescribers with experience treating patients with ASCVD were surveyed by email, resulting in a 3.3 % response rate (122 respondents). Survey data were analyzed descriptively and using regression models; interview data were analyzed thematically.

Results: While cohort patients were identified as having an ASCVD diagnosis and taking a LLT from their medical chart, only 16.8 % of respondents reported having an ASCVD diagnosis and 84.2 % reported taking LLTs. Patients taking medication reported a higher average number of health condition diagnoses compared to those not taking a medication (2.63 and 1.50, respectively). Of those taking medication, 55.7 % were identified as adherent. Non-adherent patients were more likely to report poor healthcare experiences and social determinants of health needs. Multivariable regression analysis revealed that patients were more likely to be adherent when they felt their healthcare provider always spent enough time with them and treated them with respect. Interview findings further emphasized the importance of healthcare experiences, convenience, and belief the treatment works as important factors to adherence. In contrast, prescribers perceived higher non-adherence rates, citing forgetfulness and medication inconvenience as the main barriers. However, only 10.0 % of responding prescribers reported using a tool to assess patients' medication adherence and only 42.6 % reported asking patients about changes to their medication regimens.

Conclusion: A substantial proportion of patients reported adherence to their medications, with adherence being associated with positive healthcare experiences, self-reported health conditions, perceived effectiveness of the medication, and social determinants of health needs. Prescribers perceived relatively low adherence among their patients, however only a small percent reported using tools to assess medication adherence. Comprehensive assessment tools and open communication could optimize patient care and enhance medication adherence and treatment outcomes.