Initial non-adherence to lipid-lowering medication: a systematic literature review.

Background: The impact on cardiovascular health is lost when a patient does not obtain a newly prescribed lipid-lowering medication, a situation termed "initial medication nonadherence" (IMN). This research summarizes the published evidence on the prevalence, associated factors, consequences, and solutions for IMN to prescribed lipid-lowering medication in the United States.

Methods: A systematic literature search using PubMed and Google Scholar, along with screening citations of systematic reviews, identified articles published from 2010 to 2021. Studies reporting results of IMN to lipid-lowering medications were included. Studies that evaluated non-adult or non-US populations, used weaker study designs (e.g., case series), or were not written in English were excluded.

Results: There were 19 articles/18 studies that met inclusion and exclusion criteria. Estimates of the prevalence of IMN to newly prescribed lipid-lowering medications ranged from 10 to 18.2% of patients and 1.4-43.8% of prescriptions (n = 9 studies). Three studies reported prescriber and patient characteristics associated with IMN. Hispanic ethnicity, Black race, lower Charlson Comorbidity Index score and no ED visits or hospitalization were associated with IMN. Lipid lowering prescriptions from primary care providers were also associated with IMN. Four studies described patient-reported reasons for IMN, including preference for lifestyle modifications, lack of perceived need, and side effect concerns. Four intervention studies reported mixed results with automated calls, live calls, or letters. One study reported worse clinical outcomes in patients with IMN: higher levels of low-density lipoprotein and greater risk of emergency department visits.

Conclusions: Up to one-fifth of patients fail to obtain a newly prescribed lipid-lowering medication but there is limited information about the clinical consequences. Future research should assess outcomes and determine cost-effective approaches to address IMN to lipid-lowering therapy.