title: Efficacy of cocaine contingency management in heroin-assisted treatment: Results of a randomized controlled trial.
abstract: To determine the efficacy of contingency management (CM), targeting cocaine use, as an add-on intervention for heroin dependent patients in supervised heroin-assisted treatment (HAT) with frequent cocaine use.
  
  
  
  Multi-center, open-label, parallel group, randomized controlled trial.
  
  
  
  Twelve specialized addiction treatment centers for HAT in The Netherlands; April 2006-January 2011.
  
  
  
  214 chronic, treatment-refractory heroin dependent patients in HAT, with frequent cocaine use.
  
  
  
  Routine, daily supervised diacetylmorphine treatment, co-prescribed with oral methadone (HAT), with and without 6 months contingency management for cocaine use as an add-on intervention; HAT+CM and HAT-only, respectively.
  
  
  
  Primary outcome was the longest, uninterrupted duration of cocaine abstinence, based upon laboratory urinalysis. Secondary outcome measures included other cocaine-related measures, treatment retention in HAT, and multi-domain health-related treatment response.
  
  
  
  In an intention-to-treat analysis, HAT+CM was more effective than HAT-only in promoting longer, uninterrupted duration of cocaine abstinence (3.7 weeks versus 1.6 weeks; negative binomial regression: Exp(B)=2.34, 95%-CI: 1.70-3.23; p<0.001). This result remained significant in sensitivity analyses and was supported by all secondary, cocaine-related outcome measures. Treatment retention in HAT was high (91.6%) with no difference between the groups. The improvement in multi-domain health-related treatment response during the trial was numerically higher in HAT+CM (from 37.4% to 53.1%; +15.7%) than in HAT-only (from 44.5% to 46.5%; +2.0%), but this difference was statistically not significant.
  
  
  
  Contingency management is an effective add-on intervention to promote longer, uninterrupted periods of cocaine abstinence in chronic, treatment-refractory heroin dependent patients in heroin-assisted treatment with frequent cocaine use. The trial has been registered in The Netherlands National Trial Register under clinical trial registration number NTR4728.
authors.affiliation: Central Committee on the Treatment of Heroin Addicts (CCBH), Utrecht University Medical Center, The Netherlands; Parnassia Addiction Research Centre (PARC), Brijder Addiction Treatment, Parnassia Group, The Netherlands. Electronic address: Peter.Blanken@Brijder.nl.
authors.forename: Peter
authors.initials: P
authors.lastname: Blanken
authors.affiliation: Central Committee on the Treatment of Heroin Addicts (CCBH), Utrecht University Medical Center, The Netherlands; Parnassia Addiction Research Centre (PARC), Brijder Addiction Treatment, Parnassia Group, The Netherlands; Curium, Leiden University Medical Center, Department of Child and Adolescent Psychiatry, Leiden University, The Netherlands.
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Hendriks
authors.affiliation: Central Committee on the Treatment of Heroin Addicts (CCBH), Utrecht University Medical Center, The Netherlands.
authors.forename: Ineke A
authors.initials: IA
authors.lastname: Huijsman
authors.affiliation: Central Committee on the Treatment of Heroin Addicts (CCBH), Utrecht University Medical Center, The Netherlands; Brain Center Rudolf Magnus, Utrecht University Medical Center, The Netherlands.
authors.forename: Jan M
authors.initials: JM
authors.lastname: van Ree
authors.affiliation: Central Committee on the Treatment of Heroin Addicts (CCBH), Utrecht University Medical Center, The Netherlands; Amsterdam Institute for Addiction Research (AIAR), Department of Psychiatry, Academic Medical Center, University of Amsterdam, The Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: van den Brink
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D003042:Cocaine / Q000008:administration & dosage*; D019970:Cocaine-Related Disorders / Q000188:drug therapy*; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage*; D004359:Drug Therapy, Combination; D005260:Female; D003932:Heroin / Q000627:therapeutic use*; D006556:Heroin Dependence / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008691:Methadone / Q000627:therapeutic use; D008875:Middle Aged; D009426:Netherlands; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid; D018765:Dopamine Uptake Inhibitors; D003932:Heroin; D003042:Cocaine; D008691:Methadone
keywords: Cocaine dependence; Contingency management; Heroin dependence; Heroin-assisted treatment