Background: The United States health care system faces two fundamental challenges: a high growth rate of health care spending and deficiencies in quality of care. The growth rate of health care spending is the dominant driver of our nation’s long-term federal debt, while the inconsistent quality of care hinders the ability of the health care system to maximize value for patients. To address both of these challenges, public and private payers are increasingly changing the way they pay providers—moving away from fee-for-service towards global payment contracts for groups of providers coming together as accountable care organizations. This thesis evaluates the change in health care spending and in quality of care associated with moving to global payment for accountable care organizations in Massachusetts in the first 4 years. This thesis studies the Blue Cross Blue Shield of Massachusetts Alternative Quality Contract (AQC), a global payment contract that provider organizations in Massachusetts began to enter in 2009. The AQC pays provider organizations a risk-adjusted global budget for the entire continuum of care for a defined population of enrollees insured by Blue Cross Blue Shield of Massachusetts. It also awards substantial pay-for-performance incentives for organizations meeting performance thresholds on quality measures. This work assesses its effect on spending and quality through the first 4 years of the contract. Methods: Enrollee-level claims data from 2006-2012 were used with a difference-in-differences design to evaluate the changes in spending and quality associated with the Alternative Quality Contract over the first 4 years. The study population consisted of enrollees in Blue Cross Blue Shield of Massachusetts plans (intervention group) and enrollees in commercial employer-sponsored plans across 5 comparison states (control group). Unadjusted and adjusted results are reported for each comparison between intervention and control. Changes in spending for all 4 AQC cohorts relative to control were evaluated. In adjusted analyses of spending, I used a multivariate linear model at the enrollee-quarter level, controlling for age, sex, risk score, indicators for intervention, quarters of the study period, the post-intervention period, and the appropriate interactions. For analyses of quality, an analogous model at the enrollee-year level was used. Process and outcome quality were evaluated. Results: Seven provider organizations joined the AQC in 2009, with a total of 490,167 individuals who were enrolled for at least 1 calendar year in the study period. The control group had 966,813 unique individuals enrolled for at least 1 year during the study period. Average age, sex, and risk scores before and after the AQC were similar between the two groups. In the 2009 cohort, claims spending grew on average $62.21 per enrollee per quarter less than control over 4 years (p<0.001), a 6.8% savings. Analogously, the 2010, 2011, and 2012 cohorts had average savings of 8.8% (p<0.001), 9.1% (p<0.001), and 5.8% (p=0.04), respectively, by the end of 2012. Savings on claims were concentrated in the outpatient facility setting, specifically procedures, imaging, and tests (8.7%, 10.9%, and 9.7%, respectively, p<0.001). Organizations with and without risk-contracting experience saw similar average savings of 6.3% and 7.7%, respectively, over 4 years (p<0.001). About 40% of savings were explained by lower volume. Pre-intervention trends were not statistically different between intervention and control (-$4.57, p=0.86), suggesting savings were not driven by inherently different trajectories of spending. No differences in coding intensity were found. In sensitivity analyses, estimates were robust to alterations in the model, variables, and sample. Notably, claims savings were exceeded by incentive payments to providers (shared savings and quality bonuses) in 2009-2011, but exceeded incentives payments in 2012, generating net savings. Improvements in quality among intervention cohorts generally exceeded New England and national comparisons. Quality performance on chronic care measures increased from 79.6% pre-intervention to 84.5% post-intervention in the 2009 cohort, compared to 79.8% to 80.8% for the HEDIS national average, a 3.9 percentage-point relative increase over the 4 years. Analogously, preventive care and pediatric care measures increased 2.7 and 2.4 percentage points relative to control, respectively. On outcome measures, achievement of hemoglobin A1c, LDL cholesterol, and blood pressure control grew by 2.1 percentage points per year in the 2009 cohort after the AQC, while HEDIS averages remained largely unchanged (Figure). Conclusion: After 4 years, physician organizations in the AQC had lower spending growth relative to control and generally outperformed national averages on quality measures. Shared savings coupled with quality bonuses can exceed savings on claims in initial years, but over time, savings on claims may outgrow incentive payments. Incentive payments themselves may serve meaningful purposes, as quality measures may protect against stinting and shared savings may help ease providers into risk contracts. Changes in utilization suggest that this payment model can help modify underlying care patterns, a likely prerequisite for sustainable reform. The AQC experience may be useful to policymakers, insurers, and providers embarking on payment reform. Combining global budgets with pay-for- performance may encourage organizations to embark on the delivery system reforms necessary to slow spending and improve quality.
| Identifer | oai:union.ndltd.org:harvard.edu/oai:dash.harvard.edu:1/12407606 |
| Date | 01 May 2015 |
| Creators | Song, Zirui |
| Publisher | Harvard University |
| Source Sets | Harvard University |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation, text |
| Format | application/pdf |
| Rights | open |
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