Health-related Quality of Life Consequences of Implantable Cardioverter Defibrillators
Results from MADIT II
Published in: Medical Care, v. 45, no. 5, May 2007, p. 377-385
Posted on RAND.org on January 01, 2007
BACKGROUND: Implantable cardioverter defibrillators (ICDs) improve survival and extend lives of patients with severe heart disease. OBJECTIVE: The authors sought to evaluate the impact of ICDs on health-related quality of life (HRQOL) during the first 3 years after implantation. Subjects: A total of 1089 patients from the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) were randomized to an ICD or medical treatment only. MEASURES: Health Utility Index (HUI3) at baseline, 3, 12, 24, and 36 months following randomization; survival data. RESEARCH DESIGN: The authors constructed mean profiles of HRQOL for living patients, estimated overall quality-adjusted life years (QALYs), separately by treatment arm, and calculated cumulative QALY gains/losses as the difference between the areas under the treatment specific HRQOL profiles. Multivariate fixed effect regression models were developed to impute the missing HRQOL data using baseline patient characteristics (age, gender, treatment, HUI3 score, diabetes, diuretics use, and NYHA class). Bootstrapped standard errors were calculated for the estimated differences in HRQOL gains/losses between treatment arms. Similarly, the authors performed subgroup analyses (by gender, age, and baseline NYHA class, blood urine nitrogen, ejection fraction, and QRS). RESULTS: There were no differences in QALYs loss for living patients by treatment group (-0.037, P = 0.64) or in overall QALYs loss by treatment group (0.043, P = 0.37) over 3 years. In subgroup analysis, female subjects demonstrated a trend towards greater survival benefit (0.298, P = 0.07) and overall QALYs (0.261, P = 0.14). CONCLUSIONS: Adverse effects of the ICD on HRQOL together with lower HRQOL among survivors may offset the 3-year survival benefits of ICDs.