Melissa Wei, M.D., M.P.H., M.S.

Assistant Professor
Medical SchoolInternal MedicineGeneral Medicine
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Dr. Wei is a general internist with a research focus on multimorbidity (multiple chronic conditions), nutrition, and chronic disease prevention. Her research goal is to identify risk factors associated with multimorbidity and translate these into clinical and public health interventions to optimize patient care and prevent multimorbidity incidence, progression, and complications. Closely related to this goal, she seeks to understand how multimorbidity influences clinical outcomes, healthcare cost, and policy. She is working on developing and validating a new measure to better characterize the growing population of adults with multimorbidity and identify modifiable risk factors for primary and secondary prevention of multimorbidity.

  • M.S., Epidemiology, Harvard T.H. Chan School of Public Health
  • M.D., M.P.H. Epidemiology and Biostatistics, Oregon Health & Science University School of Medicine
  • B.S., Biological Sciences, concentration in Nutritional Sciences, Cornell University

Condition Focus

U-M Academic Affiliation(s)

Featured Member Profile


What are you thinking about?
My research focuses on patients with multimorbidity, the confluence of multiple medical conditions. A few areas I’m investigating include: How do we measure and define multimorbidity? How can we optimize the care of patients with multimorbidity? How can we prevent or delay the onset, progression, and complications associated with multimorbidity through the life course?

“Multimorbidity” differs from the construct of “comorbidity,” in which a primary or "index" disease is identified, and coexisting conditions are considered comorbidities, often interpreted in the context of the index disease. In multimorbidity there is no focal index disease, and an individual is considered as the whole of his or her medical conditions without preference to a particular condition. Conditions may be secondary to, complications of, or simply co-occurring with other conditions without a shared pathogenesis.

Multimorbidity is a helpful framework for primary care and generalists who care for the overall longitudinal health of individuals. In the U.S. and many developed nations, the most commonly co-occurring chronic conditions are hyperlipidemia, hypertension, and osteoarthritis, although these differ from conditions with the worst health-related quality of life, which include progressive neurologic conditions and end-stage organ diseases.


Why is this interesting to you?
I became intrigued by multimorbidity as an internal medicine resident caring for patients in my continuity clinic at Grady Memorial Hospital. I was struck by the high prevalence of multimorbidity, even among young and middle-aged adults, who were functionally older than their age would suggest. I wanted to understand how these individuals became susceptible to acquiring several and often suboptimally controlled medical conditions, how multimorbidity would impact their long term prognosis, and ultimately how I could better care for them as their primary care provider.


What are the practical implications for healthcare?
Multimorbidity is more common than single diseases in isolation and is becoming increasingly prevalent in our aging population. While older adults are disproportionately burdened, the absolute number of adults with multimorbidity is greater among young and middle-aged adults.

Multimorbidity is associated with poor health outcomes, decreased health-related quality of life, and high healthcare utilization and cost. Even seemingly minor diseases have a lasting impact on quality of life and mortality risk over time. We have numerous studies, interventions and guidelines targeted at single diseases, but effective, high-value care for patients with multimorbidity that is also aligned with their preferences is a work in progress. Adding to this complexity is continued debate on how we define and measure multimorbidity for clinical care, research, and risk-adjustment to distinguish the potential worse state of patients with coexisting conditions compared with healthier peers.

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