Nonutilization of Statins in a Community-based Population with a History of Coronary Revascularization

Abstract

Purpose: Statin therapy has been reported to reduce the incidence of vascular events in patients with atherosclerosis, but adherence to statins may be suboptimal. The aims of this study were to quantify the rate of statin use among individuals with a history of coronary revascularization in a large, integrated health care system and to determine which demographic characteristics and clinical factors are associated with statin use.

Methods: This was a retrospective cohort study using database programming and chart review. The study included adult members of Kaiser Permanente Northern California with a history of coronary revascularization. The study outcome was off-statin status, defined as a ≥1-year gap between filled prescriptions. The predictor variables included age, race, body mass index, dyslipidemia, liver disease, kidney disease, and history of statin allergy. Multivariable logistic regression was used to quantify the associations between the predictor variables and statin status. A chart review of a randomly selected subset was performed to identify reasons why individuals were not taking statins.

Findings: The study population included 17,869 Kaiser Permanente Northern California members, of which 18.3% had off-statin status. The following variables were associated with off-statin status: statin allergy (odds ratio [OR] = 2.18; 95% CI, 1.89-2.52), end-stage renal disease (OR = 1.55; 95% CI, 1.26-1.91), liver disease (OR = 1.44; 95% CI, 1.08-1.93), African-American race (OR = 1.55 vs white; 95% CI, 1.32-1.81), and Latino race (OR = 1.18; 95% CI, 1.05-1.33). The chart review found that off-statin status typically reflects patient (79%) rather than provider (21%) preference.

Implications: A significant minority of patients with a history of coronary revascularization are not taking statins. Off-statin status is associated with kidney disease, liver disease, African-American race, and Latino race. At an individual level, off-statin status was usually driven by patient preference, due to minor or undefined reasons. These findings may be useful in guiding strategies to increase statin use in individuals with atherosclerosis.

Keywords: adherence; atherosclerosis; coronary revascularization; statin.