Payment models based on medical problems that omit social risk may underpay for vulnerable populations' treatment, according to a study recently published in JAMA Internal Medicine.
Boston University and Worcester-based University of Massachusetts Medical School researchers — led by Arlene Ash, PhD, professor of quantitative health sciences at UMass Medical School — analyzed Massachusetts' MassHealth Medicaid program enrollment and insurance claims to identify social variables influencing medical costs. Studying 2013 MassHealth data for more than 800,000 beneficiaries enrolled for at least six months, Dr. Ash and colleagues examined how determinates like ethnicity, housing, mental health, substance use, English use and disability affected Medicaid spending, comparing a diagnosis-based payment model to one they developed to account for social determinants of health.
The study found healthcare costs for beneficiaries living in the most stressed neighborhoods were roughly 23 percent higher than those in the least stressed neighborhoods. While medical risk represented most of the difference, Dr. Ash and researchers said they eliminated the last 5 percent of Medicaid underpayment for beneficiaries living in the most stressed neighborhoods by adding neighborhood stress scores in the payment model.
"A payment formula that accounts for medical problems but ignores social risk will underpay for treating vulnerable populations, potentially exacerbating already existing inequalities," Dr. Ash told UMass Med Now. "We describe a model to ensure that plans get more money for enrolling patients with greater medical and social needs."
In addition, researchers found Medicaid beneficiaries who changed addresses more than once annually had $500 more in healthcare expenses in the social determinates of health model than a diagnosis-based model calculated.
MassHealth implemented the researchers' social determinants of health payment model in 2016.