Cost-Effectiveness Analysis of a Low-Fat Diet in the Prevention of Breast and Ovarian Cancer

Background: Results of the Women's Health Initiative Randomized Controlled Dietary Modification Trial (WHI-DM) suggest that a low-fat diet may be associated with beneficial health outcomes for specific groups of women. Objective: The objective is to assess how cost-effective the WHI-DM would be if implemented as a public health intervention and under the sponsorship of private health insurers and Medicare. Breast and ovarian cancers are the health outcomes of interest. Participants: Two groups of WHI-DM participants form the target population for this analysis: participants consuming >36.8% of energy from fat at baseline, and participants at high risk for breast cancer with 32% or more of energy from fat at baseline. Methods: This study uses Markov cohort modeling, following societal and health care payer perspectives, with Monte Carlo simulations and one-way sensitivity analyses. WHI-DM records, nationally representative prices, and published estimates of medical care costs were the sources of cost information. Simulations were performed for hypothetical cohorts of women aged 50, 55, 60, 65, or 70 years at the beginning of the intervention. Effectiveness was estimated by quality-adjusted life years (QALYs) and the main outcome measure was the incremental cost-effectiveness ratio (ICER). Results: Following the societal perspective, the ICERs for the 50-year old cohort are $13,773/QALY (95% confidence interval $7,482 to $20,916) for women consuming >36.8% of energy from fat at baseline and $10,544/QALY ($2,096 to $23,673) for women at high risk for breast cancer. The comparable ICER from a private health care payer perspective is $66,059/QALY ($30,155 to $121,087) and from a Medicare perspective, it is $15,051/QALY ($6,565 to $25,105). Conclusions: The WHI-DM is a cost-effective strategy for the prevention of breast and ovarian cancers in the target population, from both societal and Medicare perspectives. Private health care payers have a relative short timeframe to realize a return on investment, since after age 65 years the financial benefits associated with the prevention program would accrue to Medicare. For this reason, the intervention is not cost-effective from a private health care payer perspective.