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
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.