The Impact of Prior Authorization on Buprenorphine Dose, Relapse Rates, and Cost for Massachusetts Medicaid Beneficiaries with Opioid Dependence

The Food and Drug Administration approved buprenorphine for medication-assisted treatment of opioid addiction in 2002. Greater flexibility in use and a better safety profile than methadone has facilitated buprenorphine's widespread adoption since then. Unlike methadone maintenance treatment, which is highly structured with most patients required to take doses at a dispensing clinic, buprenorphine patients can receive up to 30 days supply of the medication to take at home. The most widely used buprenorphine formulation in the United States combines buprenorphine with naloxone, an opioid antagonist that may reduce its abuse potential. It is sold under the brand name Suboxone. Generic equivalents of Suboxone were introduced during the first quarter of 2013, after completion of this study. Although most studies indicate that methadone maintenance therapy is somewhat more effective in preventing addiction relapse (Barnett, Zaric, and Brandeau 2001; Mattick et al. 2014; Clark et al. 2011), many providers and patients prefer buprenorphine because it is less dangerous if patients overdose and in-home administration causes fewer disruptions in employment and family life. Both forms of treatment are more effective in preventing relapses than drug free treatment alone (Mattick et al. 2009, 2014). Medicaid, a health entitlement program jointly funded by states and the federal government, funds a significant proportion of buprenorphine treatment in the United States (Ducharme and Abraham 2008; Stein et al. 2012). The greater prevalence of substance use disorders among Medicaid beneficiaries, coupled with the relatively rapid adoption and high cost of buprenorphine + naloxone (about $325 per month for the average user) has attracted the attention of Medicaid administrators. Increasing reports of diversion have also raised concerns about buprenorphine treatment in general, and dosing levels in particular, as some reports suggest that patients prescribed high doses may use only a portion of their medication and share or sell the rest (Lofwall and Havens 2012; NYTimes article 11-17-13; Wish et al. 2012). The recommended dosage for buprenorphine + naloxone maintenance is 16 mg of buprenorphine per day with an upper limit of 24 mg (Federal Drug Administration 2010). However, dosing varies widely according to patient need and provider preference (Center for Substance Abuse Treatment 2004). Concerns about cost and diversion have prompted many states to place limits on buprenorphine prescription. Almost all states now require some form of prior approval for buprenorphine prescriptions. Currently, 12 states limit the total amount of time that a Medicaid-eligible patient can be treated during his or her lifetime. Limitations in lifetime use range from 6 to 36 months, most limit treatment to 12 months (Rinaldo and Rinaldo 2013). Concerns about cost and diversion led the Massachusetts Medicaid program (MassHealth) to implement a unique prior authorization policy focused on buprenorphine dose levels in January of 2008. The policy was applied to all members of the Primary Care Clinician Plan and to fee-for-service members, for whom MassHealth directly manages pharmacy benefits. Under the new policy, higher doses required more frequent prior authorization. For example, doses above 32 mg/day required prior approval with each 30-day prescription, doses less than or equal to 32 mg/day but greater than 24 mg/day required authorization every 90 days, those greater than 16 mg/day but less than or equal to 24 mg/day, every 180 days. Prescriptions of 16 mg/day or less did not require prior authorization. Unlike some other states' requirements, the Massachusetts policy did not seek to limit access to buprenorphine, but rather to lower costs and discourage diversion by reducing doses that were higher than the recommended therapeutic range. Although prior authorization is widely used as a method for managing access to costly medications, some studies suggest that it can produce minimal savings and may actually increase costs if the added burden of the requirement leads to a break in treatment continuity or to greater treatment dropout rates (Law, Ross-Degnan, and Soumerai 2008; Abouzaid et al. 2010; Lu et al. 2011). Prior authorization policy effects can vary depending upon the type of drug to which they are applied, the population being served, and specific details of the policy. For example, a study of expensive nonsteroidal antiinflammatory drugs found significant reductions in use after implementation of prior authorization requirements in several states (Fischer et al. 2004) but prior authorization was found to have minimal effects on prescribing of oxycodone, a pain medication with high addiction potential (Morden et al. 2008). The effects of prior authorization requirements on buprenorphine use, costs, and outcomes have not previously been studied. To understand the impact of MassHealth's policy, we examined changes in dosing, relapse rates, medication costs, and total health care costs per person before and after implementation of the 2008 policy. We also explored changes in rates of treatment discontinuation or switching.