Helena Roy

Helena Roy

I'm an economist studying how innovation — technological, institutional, and informational — changes the way health decisions get made.

My goal is to understand the optimal design and deployment of new information technologies in healthcare — accounting for variation in behaviour — so people can make well-informed choices about their health, and improve the outcomes that follow. In current research, I consider how people seek out health information online, and how diagnostic innovation happens, among other topics. I work on these questions as a postdoctoral fellow in Professor Ariel Stern's group on digital health, economics, and policy, at the Hasso Plattner Institute.

Alongside my research, I actively work with healthtech start-ups, and am a (non-resident) fellow at the Centre for British Progress. I hold a PhD in Economics from Stanford, an MPhil from Oxford, and a BA from Cambridge. I'm from the UK and Aotearoa New Zealand, and enjoy outdoor activities, reading, and flat whites.

Research

Work in progress
Measuring Diagnostic Innovation in Artificial Intelligence-Enabled Medical Devices
Mapping Health Information in Online Communities
Race and Patient Use of AI and Online Search Tools
with Helen Kissel and Tamri Matiashvili
Physician Training and Patient Heterogeneity: Evidence from Residency
with Helen Kissel
Healthcare Delivery Innovation: The Impact of Birth Centers on Maternal and Infant Health
with Helen Kissel, Ambar La Forgia, Petra Persson, and Maya Rossin-Slater
Presented at ASHEcon 2025
Working papers — drafts available upon request
Gender, Information, and Online Search for Physicians
with Helen Kissel and Tamri Matiashvili
Presented at Stanford SITE 2026
Abstract

Patients increasingly select physicians through online “find a doctor” tools, which display information such as physician gender and patient ratings, rather than relying on physician referral, word-of-mouth, or soonest availability. Medical literature documents female patients' stated preferences for female physicians in certain specialties, but whether and how patients act on these preferences when given the tools to do so remains an open question. Using a randomized hypothetical choice experiment that mirrors the information presented in typical online physician-search platforms, we find that female patients have strong preferences for gender-concordant physicians in gender-sensitive specialties. Women are willing to wait 1.6 additional weeks for a female urologist and 2.2 additional weeks for a female psychiatrist, two specialties with more gender-sensitive components, but show no statistically significant concordance preference in orthopedics, a more gender-neutral specialty. Men exhibit no significant concordance preference in any specialty. Among women, the gender concordance preference is stronger among those who report prior negative healthcare experiences due to gender. We complement these experimental findings with evidence from Medicare claims data on bladder cancer patients. We find that female patients are more likely than male patients to see female urologists, and women who match with a female urologist wait longer than women who match with a male urologist. Male patients exhibit no corresponding wait-time difference by physician gender. These findings suggest that patient preferences over physician characteristics, and patients' growing capacity to act on those preferences, mean that the availability of female healthcare providers may affect patterns of health-seeking behavior such as provider choice and timing of care.

Understanding Variation in Cesarean Section Use: Supply-Side Drivers and Maternal Health Effects
with Helen Kissel
Presented at ASHEcon 2025
Abstract

We estimate the causes and consequences of regional variation in healthcare utilization in the setting of Cesarean sections (C-sections), the most common inpatient surgery in the United States. C-section rates differ up to 10-fold across hospitals, with substantial variation even for clinically similar patients. Using nationwide Medicaid administrative claims data, we leverage physician mobility across hospitals to disentangle the role of physician practice style from hospital environment. We find that differences in physician practice style can explain approximately 20% of the across-hospital differences in C-section rates. This variation in practice style has meaningful consequences for patient health: low-risk patients quasi-randomly assigned to more C-section-intensive physicians are 28% more likely to deliver via unplanned C-section, leading to higher rates of maternal and infant health complications and worse maternal mental health postpartum. Our findings highlight physician practice style as an important driver of variation in obstetric care with direct consequences for maternal and infant health.

Published articles
Mihir A Kelshiker, Patrik Bächtiger, Camille F Petri, Saloni Nakhare, Josephine Mansell, Karanjot Chhatwal, Abdullah Alrumayh, Jahed Zaman, Moulesh Shah, Holly Young, Helena Roy, Melanie T Almonte, Céire Costelloe, Yasmin Razak, Azeem Majeed, James P Howard, Carys Barton, Daniel B Kramer, Carla M Plymen, and Nicholas S Peters
The Lancet, 2026, 407(10529): 704–715
Summary

Early detection of cardiovascular disease is a global public health priority. Artificial intelligence (AI)-enabled stethoscopes offer robust performance characteristics in point-of-care detection of heart failure, atrial fibrillation, and valvular heart disease (VHD). We conducted a pragmatic, cluster-randomised controlled implementation trial to determine the real-world effect and implementation challenges of AI-stethoscopes. We found that implementation of an AI stethoscope in routine primary care did not significantly increase detection of heart failure or increase community-based diagnosis after 12 months of implementation. However, AI stethoscope use was independently associated with significantly higher detection rates of heart failure, as well as atrial fibrillation and VHD. This randomised controlled implementation trial establishes a pragmatic design with randomisation that generates real-world data essential for understanding and overcoming the barriers to implementation of innovation in health care.

Other

I have written various briefings exploring how policy can encourage economic growth through innovation. One public example, on sovereign AI bonds, won Best Policy Proposal in Erik Brynjolfsson's AI Awakening Seminar at Stanford in 2024, was published by UK Day One, and presented as part of LSE and Anthropic's Economic Symposia in 2025.

Contact

You can reach me by email here.