Effectiveness and cost-effectiveness of implantable cardioverter defibrillators in the treatment of ventricular arrhythmias among Medicare beneficiaries

PURPOSE: The implantable cardioverter defibrillator has been assessed in randomized trials, but the generalizability of trial results to broader clinical settings is unclear. Our purpose was to evaluate the outcomes and costs of defibrillator use in an unselected population. SUBJECTS AND METHODS: We identified 125,892 Medicare patients who were discharged between 1987 and 1995 after hospitalization with a primary diagnosis of ventricular tachycardia or ventricular fibrillation, 7789 of whom (6.2%) received a defibrillator. We used a multivariable propensity score that included patient and hospital characteristics to match pairs of patients, in which one patient received a defibrillator and the other did not. We compared mortality and costs in these 7612 matched pairs during 8 years of follow-up. RESULTS: Patients who received a defibrillator were more likely to be younger, white, male, and urban dwelling, and to have ischemic heart disease, heart failure, or a history of ventricular fibrillation. In the matched-pairs analysis, those who received a defibrillator had significantly lower mortality: 11% versus 19% at 1 year (odds ratio [OR] = 0.57; 95% confidence interval [CI]: 0.51 to 0.63), 20% versus 30% at 2 years (OR = 0.66; 95% Cl: 0.60 to 0.72), and 28% versus 39% at 3 years (OR = 0.70; 95% CI: 0.63 to 0.77). These patients also had lower mortality at 8 years (P = 0.0001), although this advantage over patients who received medical treatment only decreased over time. Expenditures among defibrillator recipients were consistently higher, with a cost-effectiveness ratio of $78,400 per life-year gained. CONCLUSION: The use of implantable defibrillators was associated with significantly lower mortality and higher costs, whereas the cost-effectiveness was higher than many, but not all, generally accepted therapies.