Effect of statin (HMG-Co-A-reductase inhibitor) use on 1-year mortality and hospitalization rates in older patients with cardiovascular disease living in nursing homes

Charles B. Eaton, The Warren Alpert Medical School
Kate L. Lapane, Brown University
John B. Murphy, The Warren Alpert Medical School
Anne L. Hume, The Warren Alpert Medical School

Abstract

OBJECTIVES: To quantify the effect of statins on 1-year mortality, hospitalizations, and decline in physical function among patients with cardiovascular disease (CVD) aged 65 and older living in nursing homes. DESIGN: Retrospective cohort study. SETTING: All Medicare/Medicaid certified nursing homes (N = 1,492) in Maine, New York, Mississippi, and South Dakota. PARTICIPANTS: We identified 51,559 older patients with CVD from a population database that merged sociodemographic data and functional, clinical, and drug treatments from more than 300,000 newly admitted nursing home residents from 1992 to 1997. Statin users (n = 1,313) were matched with nonusers (n = 1,313) in the same facilities. MEASUREMENTS: All-cause mortality, hospitalization, combined endpoint of mortality or hospitalization, and decline in physical function were determined at 1 year, and survival analysis was performed. RESULTS: Prevalence of statin use in this frail older cohort with CVD was 2.6%. Statin use varied by age, gender, comorbid condition, medication use, and cognitive and physical function. One-year mortality was 229/1,000 person-years in the statin group and 404/1,000 person-years in the nonusers, with an adjusted hazard rate ratio (HRR) of 0.69, 95% confidence interval (CI) = 0.58-0.81. The estimated number needed to treat was seven (95% CI = 5-13). This association with improved all-cause mortality was evident for women and men and for age groups 75 to 84, and 85 and older. CONCLUSION: Statin therapy is associated with improved clinical outcomes, including reduction in 1-year all-cause mortality, and the combined endpoint of death or hospitalization in a frail older population with CVD. Some caution should be taken in interpreting these results because potential bias from residual confounding could affect these results.