Adherence to statins, subsequent healthcare costs, and cardiovascular hospitalizations

Statins are the primary agents used to decrease low-density lipoprotein cholesterol. Although adherence to statins improves the clinical outcomes, the affect of statin adherence on healthcare costs has not been well studied. To examine the relation among statin adherence, subsequent hospitalizations, and healthcare costs, we conducted a retrospective cohort study of 381,422 patients, aged 18 to 61 years, using an integrated pharmacy and medical claims database. We measured adherence using the medication possession ratio (MPR) for 12 months and the healthcare costs and cardiovascular disease-related hospitalizations during the subsequent 18 months. Of those studied, 258,013 (67.6%) were adherent (MPR ≥80%), 65,795 (17.3%) had an MPR of 60% to 79%, and 57,614 (15.1%) had an MPR of <60%. The adjusted all-cause total healthcare costs were lowest in the adherent group at $10,198 ± $39.4 (mean ± SE) versus $10,609 ± $77.7 (p <0.001) for an MPR of 60% to 79%, and $11,102 ± $84.3 (p <0.001) for an MPR of <60%. The adherent group had greater statin costs at $838 ± $1.0 versus $664 ± $2.0 (p <0.001) and $488 ± $2.2 (p <0.001). When evaluated by 5 levels of MPR, 0% to 59% and increments of 10% >60%, the adjusted total healthcare costs were lowest for the MPR 90% to 100% group and significantly greater statistically (p <0.001) for each lower level of adherence. Compared to the statin-adherent patients, cardiovascular disease-related hospitalizations were more likely for the patients with an MPR of 60% to 79% (odds ratio 1.12, 95% confidence interval 1.08 to 1.16) and an MPR of 0% to 59% (odds ratio 1.26, 95% confidence interval 1.21 to 1.31). In conclusion, statin adherence is associated with reductions in subsequent total healthcare costs and cardiovascular disease-related hospitalizations.