Research
Summary
Dr. Machado is a health economist. Her research asks how health and wealth move together from midlife onward, and what longer lives mean for the systems that finance and deliver care. She combines quasi-experimental methods with cross-national longitudinal data on older adults — the Health and Retirement Study, ELSA, and SHARE — and with administrative and clinical datasets, to show how economic resources translate into health.
Her work on wealth and mortality has shown that even the wealthiest Americans face higher mortality than their European counterparts, revealing how differently two sets of health systems turn income and wealth into years of life. Published in the New England Journal of Medicine, it drew coverage in more than 180 news outlets worldwide and entered policy debate in several countries. Related work has traced wealth-related inequalities in self-reported health across the United States and fourteen high-income countries, and linked midlife wealth mobility to long-term cardiovascular health.
A growing strand of her research addresses longevity — what longer lives mean for how care is organized and paid for. With colleagues she has examined the demand- and supply-side pressures that longer lives place on care systems, including who provides informal care across 28 countries and what that care costs carers in employment and earnings; this work is forthcoming in Nature Aging. Related projects examine how long-term care funding shapes access to life-sustaining critical care in the English NHS, how cognitive function relates to retirement expectations across global longitudinal aging studies, and how a midlife cardiovascular event affects retirement-account withdrawals and long-term financial security.
Her work in cardiovascular health economics spans the full patient journey, from risk factors and prevention to advanced intervention. Using clinical data from the United Network for Organ Sharing, she has analyzed evolving patterns in heart transplantation access, donor utilization, and the effect of comorbidities on transplant outcomes. Her pharmaceutical policy research has quantified how Medicaid expansion influenced access to cholesterol-lowering medications, and how multimarket competition shapes the regulated prices of generic drugs. She is Principal Investigator at Brown SPH for CARDIO-DAY, a consortium funded by the La Caixa Banking Foundation that evaluates the clinical, economic, and system-level impact of a cardiology day-hospital model.
Her research on health system assessment and comparative analysis includes a framework for evaluating political parties’ health proposals, applied to Portugal’s 2024 election and used to inform the national health policy debate, and an assessment of national action plans on antimicrobial resistance and their effect on antibiotic use. She has also studied health workforce dynamics, including physician density by specialty across urban and rural counties in the United States, building on earlier conceptual work on the economics of medical training and the trade-offs between different types of providers.
A further line of work examines pro-social behavior in health systems. Her doctoral research analyzed the economics of blood donation, and more recent work compares altruistic giving across causes and domains. At the intersection of technology and health care financing, she has studied fraud detection in medical crowdfunding and how race and ethnicity shape crowdfunding success.
Her methods range from econometric analysis of large administrative datasets to machine learning applications, and her work appears across premier medical journals (New England Journal of Medicine, JAMA Cardiology, JAMA Network Open), health economics and health services research journals (Health Economics, Health Services Research, Health Affairs Scholar), and computer science venues.
See CV for publication details.
Featured Research
Association Between Wealth and Mortality in the United States and Europe
with Ilias Kyriopoulos, John Orav, and Irene Papanicolas
Published April 2, 2025
N Engl J Med 2025;392:1310-1319
Background
Amid growing wealth disparity, we have little information on how health among older Americans compares with that among older Europeans across the distribution of wealth.
Methods
We performed a longitudinal, retrospective cohort study involving adults 50 to 85 years of age who were included in the Health and Retirement Study and the Survey of Health, Ageing, and Retirement in Europe between 2010 and 2022. Wealth quartiles were defined according to age group and country, with quartile 1 comprising the poorest participants and quartile 4 the wealthiest. Mortality and Kaplan–Meier curves were estimated for each wealth quartile across the United States and 16 countries in northern and western, southern, and eastern Europe. We used Cox proportional-hazards models that included adjustment for baseline covariates (age group, sex, marital status [ever or never married], educational level [any or no college education], residence [rural or nonrural], current smoking status [smoking or nonsmoking], and absence or presence of a previously diagnosed long-term condition) to quantify the association between wealth quartile and all-cause mortality from 2010 through 2022 (the primary outcome).
Results
Among 73,838 adults (mean [±SD] age, 65±9.8 years), a total of 13,802 (18.7%) died during a median follow-up of 10 years. Across all participants, greater wealth was associated with lower mortality, with adjusted hazard ratios for death (quartile 2, 3, or 4 vs. quartile 1) of 0.80 (95% confidence interval [CI], 0.76 to 0.83), 0.68 (95% CI, 0.65 to 0.71), and 0.60 (95% CI, 0.57 to 0.63), respectively. The gap in survival between the top and bottom wealth quartiles was wider in the United States than in Europe. Survival among the participants in the top wealth quartiles in northern and western Europe and southern Europe appeared to be higher than that among the wealthiest Americans. Survival in the wealthiest U.S. quartile appeared to be similar to that in the poorest quartile in northern and western Europe.
Conclusions
In cohort studies conducted in the United States and Europe, greater wealth was associated with lower mortality, and the association between wealth and mortality appeared to be more pronounced in the United States than in Europe.