Graduate Thesis Or Dissertation


Effect of Accountable Care in Oregon Medicaid on Healthcare Utilization, Quality, and Spending among Children with Mental-Physical Comorbidities Public Deposited

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  • In 2012, Oregon began it enrolling its Medicaid beneficiaries in an accountable care model called Coordinated Care Organizations (CCOs). As one of the of the earliest state-wide efforts to implement this type of healthcare reform among Medicaid enrollees, and thus one of the most mature, Oregon’s CCO implementation provided a natural experiment to explore the effects of a unique healthcare system that focuses on patient-centered primary care home enrollment, integration of physical, behavioral, and oral healthcare, and payment arrangements that emphasize value over volume. This dissertation, consisting of two studies, examined the impact of Oregon’s CCO implementation on healthcare utilization, quality, and spending among children aged three to 18 with mental-physical comorbidities (MPCs). In addition, this research investigated whether the CCO model exhibited heterogeneous effects on healthcare utilization and quality between children with and without MPCs, and if the effect of CCO implementation on healthcare spending differed based on level of spending among children with MPCs. Using a quasi-experimental design and difference-in-differences (DID) framework, Study 1 examined whether and the extent to which the CCO model was associated with changes in healthcare utilization and quality during the first three years after CCO implementation. Using Medicaid claims and enrollment data from January 2009 to December 2015, I created a child-year panel data set that consisted of 25,940 children continuously enrolled in Oregon Medicaid who were either continuously enrolled in CCOs during the CCO period (n=24,496 children) or never enrolled in CCOs (n=1,444 children). Healthcare utilization outcomes included number of preventive care, emergency department (ED), and hospital services. Healthcare quality outcomes included receipt of recommended annual well-care visit and receipt of recommended annual depression screening, and number of potentially avoidable ED visits, mental illness-related ED visits, and 30- and 90-day hospital readmissions. This study found CCO implementation was not associated with statistically significant improvements in preventive care or hospital utilization or quality, but was associated with small increases in the number of all-cause and potentially avoidable ED visits among children with MPCs. Relative to children without MPCs or medical complexity, children with MPCs had increased probabilities of utilizing preventive care and receiving recommended annual well-care visits following CCO implementation. Next, using a unique data set on fee-for-services, managed care, and CCO Medicaid healthcare payments and a quasi-experimental DID framework, Study 2 explored whether and the extent to which CCO implementation was associated with changes in Medicaid spending. Medicaid claims and enrollment data were matched with Medicaid payment data from January 2012 to September 2015 to create a child-month panel data set that consisted of 28,665 children continuously enrolled in Oregon Medicaid who were either continuously enrolled in CCOs during the CCO period (n=27,465 children) or never enrolled in CCOs (n=1,200 children). Healthcare spending outcomes included total, preventive, ED, and hospital monthly Medicaid spending. This study indicated that on average, the CCO model was associated with a statistically significant reduction in total monthly Medicaid spending among children with MPCs that, if summed across the study population enrolled in CCOs, amounted to nearly $1.5 million in Medicaid savings each year (2015 dollars). Although not statistically significant, consistent patterns of healthcare spending reductions were observed following CCO implementation for all types of services other than ED services. In addition, the CCO model was associated with differential impacts on Medicaid spending at different quantiles of the spending distributions for total and preventive care spending, but was not associated with statistically significantly different effects at different quantiles of ED or hospital spending. Despite facing challenges in meeting some of their quality and access goals, the CCO model provides a solid foundation for the delivery of high-quality pediatric care, with features like providing patient- and family-centered care in medical homes and integrating physical and behavioral healthcare. CCOs should, therefore, pursue strategies that modify the existing model in such a way that quality of and access to primary, preventive, and specialty care is improved, and health events and complications that require acute care such as ED and hospital visits are reduced among children with complex and comorbid conditions. This, in turn, should also aid CCO’s in their cost growth-containment goals. Oregon has developed detailed plans to intensify CCOs’ focus on physical and behavioral health integration, significantly expand the use of value-based payment arrangements and financial support for patient-centered primary care homes, and invest in social determinants of health and health equity. Future research should investigate whether these changes to Oregon’s Medicaid healthcare delivery and finance model improve healthcare access and quality and reduce healthcare spending among medically complex populations like children with MPCs.
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  • This project was supported by grant number R36HS027163 from the Agency for Healthcare Research and Quality. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Agency for Healthcare Research and Quality.
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