acase@tulane.edu / 1 / Yongkang Zhang

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.

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Amidst mounting federal debt, slowing the growth of health care spending is one of the nation’s top domestic priorities. This dissertation evaluates three current policy ideas: (1) global payment within an accountable care contracting model, (2) physician fee cuts, and (3) expanding the role of competitive bidding in Medicare. Chapter one studies the effect of global payment and pay-for-performance on health care spending and quality in accountable care organizations. I evaluate the Blue Cross Blue Shield of Massachusetts Alternative Quality Contract (AQC), which was implemented in 2009 with seven provider organizations comprising 380,000 enrollees. Using claims and quality data in a quasi-experimental difference-in-differences design, I find that the AQC was associated with a 1.9 percent reduction in medical spending and modest improvements in quality of chronic care management and pediatric care in year one. Chapter two studies Medicare’s elimination of payments for consultations in the 2010 Medicare Physician Fee Schedule. This targeted fee cut (largely to specialists) was accompanied by a fee increase for office visits (billed more often by primary care physicians). Using claims data for 2.2 million Medicare beneficiaries, I test for discontinuities in spending, volume, and coding of outpatient physician encounters with an interrupted time series design. I find that spending on physician encounters increased 6 percent after the policy, largely due to a coding effect and higher office visit fees. Slightly more than half of the increase was accounted for by primary care physician visits, with the rest by specialist visits. Chapter three examines competitive bidding, which is at the center of several proposals to reform Medicare into a premium support program. In competitive bidding, private plans submit prices (bids) they are willing to accept to insure a Medicare beneficiary. In perfect competition, plans bid costs and thus bids are insensitive to the benchmark. Under imperfect competition, bids may move with the benchmark. I study the effect of benchmark changes on plan bids using Medicare Advantage data in a longitudinal market-level model. I find that a $1 increase in the benchmark leads to about a $0.50 increase in bids among Medicare managed care plans.

Consolidating patient and clinical data to support better-informed clinical decisions remains a primary function of electronic health records (EHRs). In the United States, nearly 6 million patients receive care from an accountable care organization (ACO). Knowledge of clinical decision support (CDS) tool design for use by physicians participating in ACOs remains limited. The purpose of this quantitative study was to examine whether a significant correlation exists between characteristics of alert content and alert timing (the independent variables) and physician perceptions of improved ACO quality measure adherence during electronic ordering (the dependent variable). Sociotechnical theory supported the theoretical framework for this research. Sixty-nine physician executives using either a Cerner Incorporated or Epic Systems EHR in a hospital or health system affiliated ACO participated in the online survey. The results of the regression analysis were statistically significant, R2 = .108, F(2,66) = 3.99, p = .023, indicating that characteristics of alert content and timing affect physician perceptions for improving their adherence to ACO quality measures. However, analysis of each independent variable showed alert content highly correlated with the dependent variable (p = .007) with no significant correlation found between workflow timing and the dependent variable (p = .724). Understanding the factors that support physician acceptance of alerts is essential to third-party software developers and health care organizations designing CDS tools. Providing physicians with improved EHR-integrated CDS tools supports the population health goal of ACOs in delivering better patient care.

<div>This dissertation consists of three chapters. The first chapter, Inertia and Switching in Health Insurance Plans, seeks to examine health insurance choice of families and individuals employed by a large Midwestern public university during the years 2012-2016. A growing number of studies indicate that consumers do not understand the basics of health insurance, make inefficient plan choices, and may hesitate to switch plans even when it is optimal to do so. In this study, I identify what are later defined as unanticipated, exogenous health shocks in the health insurance claims data, in order to examine their effect on families' plan choice and switching behavior. Observing switches into relatively generous plans after a shock is indicative of adverse selection. Adverse retention and inertia, on the other hand, may be present if people remain in the relatively less generous plans after experiencing a shock. The results could help inform the policy-makers about consumer cost-effectiveness in plan choice over time.</div><div> Physicians’ relationships with the pharmaceutical industry have recently come under public scrutiny, particularly in the context of opioid drug prescribing. The second chapter, Pharmaceutical Opioid Marketing and Physician Prescribing Behavior, examines the effect of doctor-industry marketing interactions on subsequent prescribing patterns of opioids using linked Medicare Part D and Open Payments data for the years 2014-2017. Results indicate that both the number and the dollar value of marketing visits increase physicians’ patented opioid claims. Furthermore, direct-to-physician marketing of safer abuse-deterrent formulations of opioids is the primary driver of positive and persistent spillovers on the prescribing of less safe generic opioids - a result that may be driven by insurance coverage policies. These findings suggest that pharmaceutical marketing efforts may have unintended public health implications.</div><div> The third chapter, Accountable Care Organizations and Physician Antibiotic Prescribing Behavior, examines the effects of Accountable Care Organizations (ACOs). Physician accountable care organization affiliation has been found to reduce cost and improve quality across metrics that are directly measured by the ACO shared savings program. However, little is known about potential spillover effects from this program onto non-measured physician behavior such as antibiotic over-prescribing. Using a two-part structural selection model that accounts for selection into treatment (ACO group), and non-treatment (control group), this chapter compares physician/nurse antibiotic prescribing across these groups with adjustment for geographic, physician, patient and institutional characteristics. Heterogeneous treatment responses across specialties are also estimated. The findings indicate that ACO affiliation helps reduce antibiotic prescribing by 23.9 prescriptions (about 19.4 percent) per year. The treatment effects are found to vary with specialty with internal medicine physicians experiencing an average decrease of 19 percent, family and general practice physicians a decrease of 16 percent, and nurse practitioners a reduction of 12.5 percent in their antibiotic prescribing per year. In terms of selection into treatment, the failure to account for selection on physician unobservable characteristics results in an understating of the average treatment effects. In assessing the impact of programs, such as the ACO Shared Savings Program, which act to augment how physicians interact with each other and their patients, it is important to account for spillover effects. As an example of such spillover effect - this study finds that ACO affiliation has had a measurable impact on physician antibiotic prescribing.</div>