The brief abstinence test: voucher-based reinforcement of cocaine abstinence

This study assessed the effectiveness of a brief abstinence reinforcement p rocedure for initiating cocaine abstinence in methadone maintenance patient s. On Monday of the test week, 72 cocaine-abusing methadone patients were o ffered a $100 voucher if urine samples collected on Wednesday indicated tha t they had abstained from cocaine across that 2-day period. A patient was c onsidered abstinent and the voucher delivered if the urine benzoylecgonine concentration decreased by 50% from Monday to Wednesday (quantitative crite rion) or if the concentration of Wednesday's urine sample was less than or equal to 300 ng/ml. Overall, 79% of study patients showed urinalysis eviden ce of abstention from cocaine between Monday and Wednesday of the test week . In a subsample with complete data (n = 50), significantly more patients a bstained from cocaine from Monday to Wednesday of the test week (84%) than from Monday to Wednesday of the week before (36%) or after (32%) the test w eek. Furthermore, while almost all patients (94%) decreased their benzoylec gonine concentration from Monday to Wednesday of the test week, significant ly fewer patients' benzoylecgonine concentrations decreased from Monday to Wednesday of the week before (56%) or after (48%) the test week. This highl y efficacious procedure may have clinical application where reliable abstin ence initiation is desired, either on a temporary basis (e.g. sobriety samp ling) or at the start of longer-term interventions. It may also be possible to use the brief abstinence test as an experimental model to assess the ef fects of other therapeutic interventions on abstinence initiation in treatm ent settings. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.