Background: In cost-effectiveness analysis (CEA), the effects of health-care interventions on multiple health dimensions typically require consideration of both quantity and quality of life.
Objectives: To explore the impact of alternative approaches to quality-of-life adjustment using patient preferences (utilities) on the outcome of a CEA on use of tamoxifen for breast cancer risk reduction.
Research Design: A state transition Markov model tracked hypothetical cohorts of women who did or did not take 5 years of tamoxifen for breast cancer risk reduction. Incremental quality-adjusted effectiveness and cost-effectiveness ratios (ICERs) for models including and excluding a utility adjustment for menopausal symptoms were compared with each other and to a global utility model.
Subjects: Two hundred fifty-five women aged 50 and over with estimated 5-year breast cancer risk ≥1.67% participated in utility assessment interviews.
Measures: Standard gamble utilities were assessed for specified tamoxifen-related health outcomes, current health, and for a global assessment of possible outcomes of tamoxifen use.
Results: Inclusion of a utility for menopausal symptoms in the outcome-specific models substantially increased the ICER; at the threshold 5-year breast cancer risk of 1.67%, tamoxifen was dominated. When a global utility for tamoxifen was used in place of outcome-specific utilities, tamoxifen was dominated under all circumstances.
Conclusions: CEAs may be profoundly affected by the types of outcomes considered for quality-of-life adjustment and how these outcomes are grouped for utility assessment. Comparisons of ICERs across analyses must consider effects of different approaches to using utilities for quality-of-life adjustment.
From the *Department of Family and Community Medicine, University of California, Davis, Sacramento, California; †Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada; ‡Center for Health Care Policy and Research, University of California, Davis, Sacramento, California; §Department of Economics, University of California, Davis, California; and ¶Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, California.
Supported by National Cancer Institute grant R01 CA86043.
The National Cancer Institute had no role in the design and conduct of the study, collection, management, analysis and interpretation of the data, or in preparation or approval of the manuscript.
Reprints: Joy Melnikow, MD, MPH, Department of Family and Community Medicine, 4860 Y Street, Suite 2300, Sacramento, CA 95817. E-mail: email@example.com.