Date of Award

January 2019

Document Type

Open Access Thesis

Degree Name

Medical Doctor (MD)

Department

Medicine

First Advisor

Joseph S. Ross

Abstract

Controlling the cost of prescription drugs is integral to improving health outcomes, and patient access and adherence to treatment. While prescription drugs can often provide essential therapeutic benefit, previous studies have suggested that inappropriate prescription drug use is a principal cause of adverse drug events as well as abuse and diversion of drugs. Thus, balancing the benefits and harms to promote appropriate prescription drug use is an essential component of healthcare delivery in the United States. There are multiple ways appropriate prescription drug use is promoted. Black-box warnings and drug labeling controlled by the FDA as well as guidelines released by the CDC, such as the 2013 guidelines released during the opioid epidemic, aim to promote appropriate prescription at a population level. At a patient-level, drug formularies have multiple strategies in place to promote safe and cost-effective prescribing of individual medications.

The Center for Medicare & Medicaid Services (CMS) makes use of prescription drug formularies that are used for the coverage of around 17% of the US population. These formularies have uniformly adopted utilization management strategies, such as quantity limits, prior authorization, and step therapy, in order to promote safe, evidence-based and cost-effective prescribing. These strategies are in place to impact drug prescription rates as well as to incentivize use of biological or therapeutically interchangeable generics over brand-name drugs. Thus far, the implementation of utilization management strategies for commonly prescribed drugs has not been thoroughly studied.

This study presents three main analyses conducted and published in the peer reviewed literature during my time in medical school. The first characterized the change in opioid prescription versus non-opioid analgesics in both the outpatient and emergency room setting in the context of the 2013 CDC guidelines encouraging prescription on non-opioid analgesic alternatives. We found that overall rates of pain medication prescribing were high and that opioid pain medication prescription increased in the outpatient setting only, whereas non-opioid pain medication prescribing increased in both the outpatient and ED settings, an area that has not been previously reported or well-investigated.

The second study characterized how Medicare formulary restrictions were applied to opioid “potentiators”, which are commonly used in conjunction with opioids and increase patients’ risk of adverse events. We found that from 2013-2017, Medicare prescription drug plan formularies had relatively unchanged rates of benzodiazepine, non-benzodiazepine sedative-hypnotic, and gabapentinoid coverage with small increases in use of quantity limits, and that more than a quarter of formularies provided unrestrictive coverage of these potentially unsafe opioid potentiators in 2017.

The third and final study herein presents a more global analysis of whether Medicare used formulary restrictions to promote prescription of therapeutically interchangeable generics over the top 100-grossing brand-name drugs in light of the 2020 CMS plans for an indication-based formulary design. We showed that a substantial portion of CMS formularies provided similarly restrictive coverage of brand-name drugs and their therapeutically interchangeable generics, including the same tier placement or utilization management, thereby missing opportunities to incentivize prescribing of less costly generics.

Overall, the results of this comprehensive study on safe and cost-effective drug prescription showed that while current formulary design includes opportunities to reduce costly and potentially unsafe prescribing, the impact of these tools is sub-optimal. These results highlight the need for both physician and patient education on the utility of the formulary restriction strategies. On a larger scale, it suggests that these strategies alone may not be sufficient to reduce over-prescription of potentially unsafe drugs like opioid potentiators, or to incentivize prescription of cost-saving generics over brand-name drugs. The Center for Medicare & Medicaid Services (CMS) has proposed an indication-based formulary design starting in 2020, allowing Medicare Advantage and Part D prescription drug plans to cover drugs only for select indications, which could increase formulary negotiating power and secure more competitive pricing. This might be the change needed in order to ensure continued patient access to affordable and safe prescription drugs.

Comments

This is an Open Access Thesis.

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