The Risk Stratification Index (RSI) is proven again to be a reliable baseline risk predictor


By Paul Manberg

How do we get more value out of limited health care dollars? One strategy is to use a risk stratification tool that helps avoid expensive downstream events by identifying which patients should be selected for additional surveillance and earlier intervention if needed. AI-driven predictors that use administrative data are attractive because the data is readily available and adheres to a common format. But does the predictor retain its power when regional coding differences are considered? In the case of one predictor the answer is yes.

RSI, an all-cause mortality predictor, has once again been shown to be a reliable baseline risk indicator. In a recent paper published in BMJ Open, the study authors concluded that “The RSI reliably tracked mortality, independently of regional coding practices and thus represents a promising method for adjusting baseline patient risk and comparing hospitals across various regions of the USA.”  1 

Researchers from Health Data Analytics Institute collaborated with a team from the Lown Institute, the Harvard T.H. Chan School of Public Health and Outcomes Research at the Cleveland Clinic to describe how RSI can be used to account for regional variations in underlying health status and coding practices. According to the Cleveland Clinic’s Outcomes Research site: “The Risk Stratification Index (RSI) is an open source, nationally validated, risk stratification methodology that permits outcomes such as duration of hospitalization and mortality to be compared equally across institutions.”

The objective of this study was to test the hypothesis that regional variations in diagnostic frequency in inpatient records are a reliable indicator of true underlying health risks. Two methods of risk stratification  were compared: (1) the number of chronic conditions; and (2) quartiles of RSI-defined risk. In addition, six socioeconomic indicators (percentages of smoking, obesity, education more than college, African/Black-American status, family household marriage status and median income) were also studied as potential factors associated with the primary all-cause annual mortality outcome measure.

Results demonstrate that regional diagnostic frequencies among inpatients are not a consequence of over-coding but do reflect higher baseline health risk. In addition, findings also indicate that RSI accounts for the impact of common socioeconomic determinants of health and offered greater resolution than counts of chronic conditions. The full paper is available here

RSI accounts for multiple inputs: including socioeconomic factors, regional health status variation, the number of chronic conditions, hospital practices, and outcome measures 

1 Li L, Chamoun GF, Chamoun NG, et al Elucidating the association between regional variation in diagnostic frequency with risk-adjusted mortality through analysis of claims data of Medicare inpatients: a cross-sectional study. BMJ Open 2021;11:e054632. doi:10.1136/bmjopen-2021-054632  


Study authors and affiliations

Linyan Li: School of Data Science, City University of Hong Kong, Hong Kong, China and the Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA

George F Chamoun: Health Data Analytics Institute, Dedham, MA, USA

Nassib G Chamoun: Health Data Analytics Institute, Dedham, MA, USA 

Daniel Sessler: Outcomes Research, Cleveland Clinic, Cleveland, OH, USA 

Valérie Gopinath: Lown Institute, Needham, MA, USA

Vikas Saini: Lown Institute, Needham, MA, USA

Your privacy matters

We believe that an individual’s meaningful control over their own data is as valuable as the data itself. That’s why we are committed to protecting privacy at every turn.
We always:
  • Provide transparency about the information we collect and why we collect it
  • Comply with all applicable privacy rules and regulations
  • Delete personal data from our servers if an individual opts out
We never:
  • Sell data to third parties
  • Share data with third parties besides the primary, explicitly authorized institution
  • Collect data besides what is disclosed
  • Keep personal data for individuals who have opted out

We speak legalese only when we have to, but we do our best to keep it human. Provided below are the full versions of our Privacy Policy and Terms of Service. If you have any questions, don’t hesitate to contact us for clarification.

George Pace

VP Business Development, Payer Markets

George has over two decades of consulting, business development and client success experience in health care, working with both providers and payers to address their most pressing challenges. The bulk of his healthcare career was with The Advisory Board, Optum, Premier and Verisk Health, with a focus on risk mitigation, value-based care and population health management. He is deeply passionate about helping healthcare organizations do their best for their patients and beneficiaries. 

When he’s not working, you will find him playing guitar, riding his bike or spending time with family, friends, and his dog Luna.  

Summer Kramer
VP Clinical Programs

Summer is a clinical pharmacist with over 15 years of experience in the healthcare industry, including hospitals, payors, and start-ups. Summer has focused her career on clinical program development and healthcare analytics with a constant drive to improve patient outcomes.

Residing in the pacific northwest, Summer enjoys hiking, camping, sailing, and traveling. She received her PharmD from the University of New Mexico, College of Pharmacy.  

Karan (Kay) Mansukhani
VP Business Development

Kay has a decade of experience in population health analytics.  Starting his career in Maryland’s state-designated HIE – CRISP,  he was entrusted to set up the infrastructure and data elements needed by health system to achieve CMMIs Triple Aim. Kay is a trained epidemiologist who has a passion for preventive medicine, psychology, and anthropology. Kay enjoys spending lazy days with his wife Sonal, and son Avtar on the beach.  Kay also enjoys listening to podcasts, playing the guitar and badminton. He received his joint MPH MBA from Johns Hopkins University.

Kevin Sampson
VP Finance

Kevin is a CPA with 25 years of executive and managerial experience in accounting, corporate finance, and operations in a variety of industries including medical device, biotechnology, and pharmaceuticals.

By listening and connecting with people, Kevin understands that accurate timely information is vital for everyone in the healthcare system. He received a BS in Accounting and an MBA in Finance and Entrepreneurial Studies from Babson College.

Paul Manberg
VP Clinical and Regulatory Affairs

Paul is an innovative, pragmatic leader with over 40 years’ experience in the medical device and pharmaceutical industries. He has directed clinical trial programs and regulatory activities supporting the successful market introduction of numerous impactful products. He spends his leisure time on the Outer Banks of North Carolina, body surfing and fishing. He received a PhD in pharmacology from The University of North Carolina School of Medicine.

Scott Greenwald
Chief Scientist

With over 25 years’ experience in healthcare research and innovation, Scott is an unprecedented leader in his field, focusing on improved care for everyone. He is an author of over 10 US Patents and over 100 peer-reviewed abstracts and manuscripts. While he’s not immersed in research, you’ll find him playing a mean round of mini golf. He received a PhD in Medical Engineering from the Harvard-MIT Division of Health Sciences and Technology (HST).

Josh Gray VP Analytic Services

Josh has 30 years’ experience in healthcare, including The Advisory Board Company, athenahealth, and Boston Consulting Group. Across his career, he has used a wide range of conventional and unconventional data sources to understand and teach the keys to top performance among the nation’s most innovative health systems and physician groups. Josh enjoys music, hiking, traveling, and watching his daughter take part in synchronized skating competitions. He received an MBA from The Wharton School at the University of Pennsylvania and an undergraduate degree from Brown University.

Carola Endicott
VP Customer Engagement, Marketing

Carola has 30 years’ experience in healthcare, including HMOs, hospitals, and start-ups. Her knowledge and optimistic outlook in operations and leadership, and her passion for making healthcare workers’ lives easier is what drives her devotion to customer engagement. She received an EdM from Harvard University Graduate School of Education.

David Clain Chief Product Officer

David has vast experience with healthcare customers from his time at The Advisory Board Company and athenahealth. His expertise and passion for statistics, strategy, and innovative analytic insights is unrivaled, as is his devotion to the Duke Blue Devils. Looking for that “aha moment” of positive change is what drives him. He received a BA from Duke University.

Margie Ahearn

Margie has 25 years of experience in HR leadership. An avid boater, Margie has received numerous awards for excellence in HR and is always looking for challenges to grow professionally and personally. She graduated with an MBA from Southern New Hampshire University.

Nassib Chamoun
Founder and CEO

Nassib is a data scientist, lover of logistical regression and a serial entrepreneur. Previously, he was Founder and CEO of Aspect Medical Systems, a Nasdaq traded company now owned by Medtronic. Outside of work, he enjoys hosting and honing his cooking skills – specializing in Middle Eastern and outdoor feasts. He received an MS from Boston University.

Phil Devlin

Phil has 30 years of experience in executive leadership. Along his journey he’s made effective and profound change in science. Little known facts about him — he loves traveling with his family, he was in the MD Engineering program at Harvard Medical School and owns 15 patents. He received an MS from Northeastern University.

What guides our culture


We are driven to make a profound impact on US healthcare


We operate in the best interests of patients and those who serve them


We understand and protect patient privacy and health information security


We use data science to enhance, but never replace clinical expertise and judgment


We are committed to continuous learning and improvement


We bring rigor, discipline, and reliability to our work


We start with kindness, assuming good intent in others


We are committed to building a diverse, inclusive team where all employees feel welcomed and appreciated


We are committed to the well-being of our employees and their families

Our vision

We envision a healthcare system where decisions are routinely informed by personalized care profiles and predictive analytics, which will improve the health of individuals and populations.

Our mission

Deploy a versatile analytic platform that creates a shared understanding of quantified health risks to inform actions with the greatest potential to benefit patients.

Who we are

We collaborate with leading health systems and integrated delivery networks, value-based care and accountable care organizations, physician groups, and commercial payers to improve care delivery and population health while reducing costs and making efficient use of scarce clinical resources.

Phil Devlin

Phil has 30 years of experience in executive leadership. Along his journey he’s made effective and profound change in science. Little known facts about him — he loves traveling with his family, he was in the MD Engineering program at Harvard Medical School and owns 15 patents. He received an MS from Northeastern University.