Competition, Adherence, and Racial and Ethnic Disparities in the Medication-Assisted Treatment Market for Opioid Use Disorder

Abstract

Medication-Assisted Treatments (MAT) are pharmaceutical products used to treat patients' opioid use disorder and have become essential therapies in combatting the devastating effects of the United States Opioid Epidemic. However, several issues plague the MAT market, such as those related to manufacturer competition, patient adherence, and racial and ethnic treatment disparities. This dissertation studied each of these issues in individual chapters. The first chapter evaluated a defining antitrust event in the MAT market. Specifically, Reckitt Bensickler violated the Sherman Antitrust Act when they launched Suboxone Film and made false claims regarding the safety of Suboxone Tablet in order to switch patients to the film. This action, known as a product hop, allowed Reckitt to maintain high market share and prices in the MAT market for years after the expiration of their patent on Suboxone Tablet. . I determined the clinical consequences of this event by comparing observed health outcomes with predicted outcomes in a counterfactual scenario where the product hop never occurred. But for the product hop, I found that there would have been roughly 10% fewer adverse opioid events between 2010-2017 due to changes in treatment use. In response, I suggested additional scrutiny of the FDA regarding the added clinical benefit of line extensions to prevent product hops from successfully derailing generic entry. The second chapter studied the financial and clinical consequences of patient nonadherence to MATs. In particular, I estimated the effect of buprenorphine treatment gaps on adverse opioid events and monthly patient total spending, medical spending, and prescription drug spending. During months in which patients had more than half the days without MAT treatment (i.e., a “gap month”), I showed that the risk of adverse opioid events was 2.83-7.79 times higher, which translated to a $63.7-$684.6 increase in total spending in that month. I further demonstrated a large increase in medical spending in months with treatment gaps that exceeded decreases in prescription drug spending. I also found evidence of heterogeneity in effect of buprenorphine treatment gaps by dosage. Patients experienced fewer costly adverse opioid events during treatment gaps with higher dosages, likely due to protective effects of residual buprenorphine. I conclude by suggesting policymakers and practitioners increase the rate at which patients are maintained and initiated on higher dosages of buprenorphine. The final chapter of the dissertation focused on quantifying racial and ethnic MAT treatment disparities and specifically tried to measure the effect of social versus provider factors in driving these disparities. To do so, I compared base model estimates that used only indicators for race and ethnicity with additional specifications that added social vulnerability indexes, patient-provider proximity, and provider-level fixed effects. The analyses showed evidence of significant racial and ethnic disparities in MAT access and use in Medicare. They also illustrated that provider factors, such as provider bias and practice patterns, are essential modifier of MAT use in particular. As a policy recommendation, I promoted incentivizing and educating providers to expand treatment to underserved groups as well as greater investment into culturally competent addiction treatment services by state and local governments.