At the 20-week follow-up , TLFB results on the 34 that continued methadone or the 3 on Suboxone showed less opioid ( 5.6 vs. 27.6 % ; p < 0.001 ) , illicit buprenorphine ( 2.7 vs. 13.8 % ; p = 0.005 ) , benzodiazepine ( 13.5 vs. 34.5 % ; p < 0.001 ) , and marijuana ( 2.8 vs. 20.7 % ; p < 0.001 ) use than the 29 who did not continue opioid substitution therapy .