The Effect of a Payer-Mandated Decrease in Buprenorphine Dose on Aberrant Drug Tests and Treatment Retention Among Patients with Opioid Dependence.

Background: The optimal dose for office-based buprenorphine therapy is not known. This study reports on the effect of a change in payer policy, in which the insurer of a subset of patients in an office-based practice imposed a maximum sublingual buprenorphine dose of 16 mg/day, thereby forcing those patients on higher daily doses to decrease their dose. This situation created conditions for a natural experiment, in which treatment outcomes for patients experiencing this dose decrease could be compared to patients with other insurance who were not challenged with a dose decrease.

Methods: Subjects were 297 patients with opioid use disorder in a primary care practice who were prescribed buprenorphine continuously for at least 3 months. Medical records were retrospectively reviewed for urine drug test results and treatment retention. Rates of aberrant urine drug tests were calculated in the period before the dose decrease and compared to rate after it with patients serving as their own controls. Comparison groups were formed from patients with the same insurance on buprenorphine doses of 16 mg/day or lower, patients with different insurance on 16 mg/day or lower, and patients with different insurance on greater than 16 mg/day. Rates of aberrant drug tests and treatment retention of patients on 16 mg/day or less of buprenorphine were compared to that of patients on higher daily doses.

Results: The rate of aberrant urine drug tests among patients who experienced a dose decrease rose from 27.5% to 34.2% (p=0.043). No comparison group showed any significant change in aberrant drug test rates. Moreover, all groups who were prescribed buprenorphine doses greater than 16 mg/day displayed lower rates of aberrant urine drug tests than groups prescribed lower doses. Retention in treatment was also highest among those prescribed greater than 16 mg/day (100% vs. 86.8%, 90.1%, and 84.4% p=0.010).

Discussion: An imposed buprenorphine dose decrease was associated with an increase in aberrant drug tests. Patients in a control group with higher buprenorphine doses had greater retention in treatment. These findings suggest that buprenorphine doses greater than 16 mg/day are more effective for some patients and that dose limits at this level or lower are harmful.