#  Katherine Ianni 

Postdoctoral Associate, Division of Health Policy and Economics, Department of Population Health Sciences, Weill Cornell Medical College

 

 

 



*Dissertation Title:* "The Effects of Payment Incentives, Benefit Design, and Provider Organization on the Value of Care"

This dissertation explores how the design of payment systems and changes in the organization of providers affect the value and delivery of care. The first two chapters investigate how the design of the Medicare Advantage payment system and recent supplemental benefit policies affect plan offerings and beneficiaries’ utilization of care. The third chapter assesses the effects of vertical consolidation between physicians and health systems on care quality and patient steering.

**Chapter 1: Do Medicare Advantage Plans Follow Incentives to Offer New Supplemental Benefits Differentially to Historically Underserved Groups?**

The payment system establishes incentives for Medicare Advantage (MA) plans to attract and retain beneficiaries from minoritized racial and ethnic groups and those dually eligible for Medicaid (duals) by offering these groups additional benefits. We examined how these incentives resulted in differential plan offerings for these groups after a 2020 policy change granted MA plans broader flexibility in benefit design(Special Supplemental Benefits for the Chronically Ill \[SSBCI\]). We found that plans with higher shares of patients from these groups were more likely to offer SSBCI benefits: a 1 standard deviation increase in a plan’s non-white share was associated with a 20.8 percentage point ( <0.010) increase in the probability that the plan offered any SSBCI benefit. We found stronger associations in more competitive markets and for groups that can be more easily targeted with additional benefit offerings. These findings are consistent with the potential for population-based payment systems to redistribute resources to underserved groups in ways that could mitigate health care disparities; they also highlight the challenges and tradeoffs involved.

**Chapter 2: What Do We Get From Offering Supplemental Transportation in the Medicare Advantage Program?**

One of the major differences between Medicare Advantage (MA) and Traditional Medicare is the flexibility to provide extra benefits and cost reductions. The availability and type of supplemental benefits in MA has increased over time, driven by growing rebates and policy expansions. An example of a benefit that is not a medical service, but may provide additional health-related value, is non-emergency medical transportation (NEMT). NEMT may serve as a complement for medical care (i.e., increase access and use) or as a transfer of resources from plans to beneficiaries (e.g., relieves caregiver burden). In this study, we investigate the value of offering NEMT in MA. Specifically, we examine the impact of MA plans offering NEMT on enrollees’ utilization of care. To do so, we leverage the 2019 expansion of the definition of “primarily health related” supplemental benefits. We found that the offering of NEMT led to a decrease in ambulance use days of 0.008 days (95% CI, -0.016 - -0.001; =0.037), representing a 5% decrease from the pre-period treatment group mean of 0.16 use days per beneficiary per year. We found no statistically significant changes in other measures of care utilization such as overall evaluation and management, procedure, imaging, annual wellness, or emergency room visits, suggesting that the NEMT benefit may not be used or that NEMT achieves a financial transfer of resources to beneficiaries but does not affect service utilization.

**Chapter 3: Quality-of-Care Outcomes in Vertical Relationships Between Physicians and Health Systems**

Vertical relationships (ownership, affiliations, joint contracting) between physicians and health systems are increasing in the US. Many proponents of vertical relationships argue that increased spending associated with consolidation is accompanied by improvements in quality of care. In this study, we used stacked difference-in-differences to estimate the effect of vertical relationships between primary care physicians (PCPs) and large health systems on use of low-value care, post-hospitalization follow-up, utilization among patients with ambulatory care-sensitive conditions (ACSC), and timeliness of specialty care for commercially insured individuals in Massachusetts over the period 2013-2017. A patient’s PCP entering a vertical relationship had no association with the probability of follow-up within 90 days of cancer diagnosis with any oncologist but led to a 7.34–percentage point (pp) (95% CI, 2.28-12.40; =0.010) increase in the probability of follow-up with an oncologist in the health system. PCP–health system vertical relationships led to a significant decrease in fragmentation of practice site visits of −1.05 pp (95% CI, −2.05 to 0.05; =0.040). We found no effect of PCP-health system vertical relationships on patients’ low-value care or ACSC utilization. These results should be considered by policymakers when assessing the potential benefits against the demonstrated harms (spending increases) of vertical consolidation.



 

 

 





 

 

- ## Dissertation Committee Member
    
     [Laura Hatfield](/dissertation-committee-member/laura-hatfield) [Michael Chernew](/dissertation-committee-member/michael-chernew) [Michael McWilliams](/dissertation-committee-member/michael-mcwilliams) [Vilsa Curto](/dissertation-committee-member/vilsa-curto)
- ## Concentration
    
     [Methods for Policy Research](/conclabel/methodsforpolicyresearch)
- ## Graduation Year
    
     [2025](/graduation-year/2025)
- ## Role
    
     [Alumni](/people/alumni)