Abstract 326: Adherence to Statins is Associated with Fewer Cardiovascular Related Hospitalizations and ED Visits in Patients 65 and Older

Abstract

Objective To examine the relationship between adherence to statins and subsequent cardiovascular related hospitalizations (CVH) and emergency department visits (CVED) in patients 65+ years of age. Methods A retrospective cohort study of patients 65+ years of age receiving statin therapy was performed. Patients had deidentified data on medical and pharmacy claims in the Medco Health Solutions, Inc. integrated warehouse, and were continuously enrolled in coverage from January 2009 through June 2011. Medication adherence was assessed by proportion of days covered (PDC) over 1 year, and risk of CVH and CVED over the subsequent year. Patients were segmented into three adherence cohorts based on PDC: 80 to 100% (adherent), PDC 60 to 79% and PDC <60%. Risk of CVH and CVED was determined by medical claims during the subsequent 12 months. Results Among the 225,802 total eligible adults, mean age was 74.4 +/-6.0 years; 53.7% were women, 73.1% (165,060) had hypertension, 31.5% (71,069) had coronary artery disease (CAD), 14.5% (32,713) had stroke, 8.3% (18,801) had heart failure (HF) and 33.3% (75,205) had diabetes. A subset that included only Medicare Part D (Med-D) plan participants (n=17,462, mean age 73.8 +/-5.6 years) had a greater percentage of women and comorbidities vs. the non-Med-D patients (n=208,340, mean age 74.4 +/-6.0 years). Comorbidity differences between the Med-D vs. non-Med-D groups were: Women 62.7% vs. 52.3%; hypertension 89.2% vs. 71.8%; CAD 38.1% vs.30.9%; stroke 16.8% vs. 14.3%; HF 14.2% vs. 7.8%; and diabetes 56.2% vs. 31.4%, p<0.0001 for all groups. Overall, mean PDC was 84% (+/-17%) and was lower in the Med-D group at 80% (+/-21%) vs. non-Med-D group at 85% (+/-17%). The majority, 167,356 (74.1%), were adherent with PDC ≥80%; 33,453 (14.8%) had PDC of 60-79% and 24,993 (11.1%) had PDC of <60%. After adjustment for age, sex, comorbidities, year 1 hospitalizations and ED visits, and total medications, the overall risk of CVH was significantly greater with PDC 60-79% (OR 1.14; CI 1.10-1.18) and PDC <60% (OR 1.28; CI 1.23-1.33), p<0.0001 compared to PDC ≥80%. The risk of CVED was increased with PDC 60-79% (1.15; CI 1.10-1.21) and PDC <60% (OR 1.43; CI 1.35-1.51), p<0.0001 compared to PDC ≥80%. The fully adjusted risk of CVH and CVED were similar between Med-D and non-Med-D plan patients. Conclusions For patients 65+ years of age, one in four was nonadherent to statin medications. Adherence to statins was associated with an inverse risk of CVH and CVED.The risk of increased CVH and CVED was similar in Med-D plan and non-Med-D participants with nonadherence.