Duration of Medication-Assisted Treatment for Opioid Addiction: Are New State Policies Helping or Hurting Medicaid Members?

Research Objective

12 states currently place lifetime limits on the duration of opioid agonist treatment (OAT) with methadone or buprenorphine. Limits range from 6 to 36 months with most set at 12 months. We analyze the duration, outcomes and costs of opioid treatment among Massachusetts Medicaid members to understand the potential impact of treatment limitations.

Study Design

We used Medicaid enrollment, claims linked with other public data on detoxification from 2003 through 2010 to identify and compare episodes of treatment with methadone, buprenorphine or without medication. Outcome measures included episode length, time to first relapse, and Medicaid expenditures per month. We used Cox proportional hazards models to measure time to relapse and generalized estimating equations to compare costs.

Populations Studied

56,278 Massachusetts Medicaid members who were treated for opioid addiction between 2004 and 2010.

Principal Findings

We identified 108,145 episodes of treatment. 62% of buprenorphine episodes, 78% of methadone episodes, and 40% of non-medication treatment episodes lasted at least 6 months; 33% 52% and 12%, respectively, lasted 12 or more months. OAT treatment was associated with significantly longer time to relapse than non-medication treatment (hazard rates: buprenorphine .31, methadone .26.) Medicaid costs for buprenorphine and methadone treatment were significantly lower than non-medication treatment ($386 and $146 per month respectively.)

Conclusions

Treatment limits set at 12 months would end treatment for one-third of buprenorphine patients and for half of methadone patients. Switching patients to non-medication treatment would likely result in more relapses for patients and higher costs for Medicaid programs.