Effects of varying the monetary value of voucher-based incentives on abstinence achieved during and following treatment among cocaine-dependent outpatients.
OBJECTIVE
This study examined whether increasing the amount of abstinence achieved during outpatient treatment for cocaine dependence is an effective method for increasing longer-term cocaine abstinence.


METHODS
A two-condition, parallel groups, randomized controlled trial was conducted.


METHODS
The trial was conducted in a university-based research clinic.


METHODS
A total of 100 cocaine-dependent outpatients participated in the trial.


METHODS
Participants were assigned randomly to receive treatment based on the community reinforcement approach (CRA) plus voucher-based incentives set at a relatively high monetary value (maximal value = $1995/12 weeks) or CRA with vouchers set at a relatively low monetary value (maximal value = $499/12 weeks). Vouchers were earned contingent on cocaine-negative urinalysis results during the initial 12 weeks of the 24-week outpatient treatment.


METHODS
Outcomes were evaluated using urine-toxicology testing, questionnaires and other self-report instruments.


RESULTS
Increasing voucher value increased the duration of continuous cocaine abstinence achieved during the 24-week treatment period. Point-prevalence cocaine abstinence assessed every 3 months throughout an 18-month follow-up period was greater in the high- than low-value voucher conditions. The duration of abstinence achieved during treatment predicted abstinence during follow-up, although that relationship weakened over time.


CONCLUSIONS
Increasing the value of abstinence-contingent incentives during the initial weeks of treatment appears to represent an effective method for increasing during-treatment and longer-term cocaine abstinence, but the positive association of during-treatment abstinence with longer-term outcome dissipates with time.
Higgins
Stephen T
ST
Department of Psychiatry, University of Vermont, Burlington, VT 05401, USA. stephen.higgins@uvm.edu
Heil
Sarah H
SH
Dantona
Robert
R
Donham
Robert
R
Matthews
Martha
M
Badger
Gary J
GJ
D000328:Adult; D019970:Cocaine-Related Disorders / Q000191:economics / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009042:Motivation; D012055:Reinforcement Schedule; D014040:Token Economy; D016896:Treatment Outcome