The $260 million Women's Health Initiative (WHI) Estrogen Plus Progestin (E+P) clinical trial yielded a huge economic return on investment, according to a modeling study being published in Annals of Internal Medicine.

A decade ago, the NIH funded the WHI E+P clinical trial to determine the cardiovascular benefits of combined hormone therapy (cHT). The study showed that cHT use increased risk for cardiovascular disease, venous thromboembolism, and breast cancer. While the trial resulted in significant changes in clinical practice, the overall economic benefit to society has been questioned. Researchers used disease-simulation modeling informed by prescribing data and risk information from the WHI E+P trial to estimate the economic return on investment. They estimate that reduced cHT use led to 126,000 fewer breast cancer cases and 76,000 fewer cardiovascular events. These changes translated into 145,000 more quality-adjusted life-years and a net economic return of $37 billion or $140 for every dollar spent on the trial. In an accompanying editorial, Michael Lauer, M.D., director of the Division of Cardiovascular Sciences at the National Heart, Lung, and Blood Institute calls the reports of the WHI trials "seminal 'black swan' events in the history of clinical research" that had an enormous and undeniable effect on public health. The high-reward potential makes these types of trials worth the investment.

Study: Economic Return From the Women's Health Initiative Estrogen Plus Progestin Clinical Trial: A Modeling Study, J.A. Roth, R. Etzioni, T.M. Waters, M. Pettinger, J. Rossouw, G. Anderson, R.T. Chlebowski, J.E. Manson, M. Hlatky, K.C. Johnson, and S.D. Ramsey, Annals of Internal Medicine, published 5 May 2014.