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Abstinence Incentive Effects in Psychosocial Counseling Patients Testing Stimulant Positive vs Negative at Treatment Entry. Maxine L. Stitzer Johns Hopkins Univ SOM National Drug Abuse Treatment Clinical Trials Network MIEDAR Study Team. Background CTN Motivational Incentives Study.
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Abstinence Incentive Effects in Psychosocial Counseling Patients Testing Stimulant Positive vs Negative at Treatment Entry Maxine L. Stitzer Johns Hopkins Univ SOM National Drug Abuse TreatmentClinical Trials Network MIEDAR Study Team
Background CTN Motivational Incentives Study • Incentive therapies offer reinforcers for therapeutically desirable behavior change • Abstinence incentives have a strong evidence-base from small-sample efficacy research across a range of abused substances (stimulants, opiates, alcohol, marijuana) • National Drug Abuse Treatment Clinical Trials Network multi-site effectiveness study • 8 psychosocial counseling community clinics • N = 415 stimulant abusers; cocaine or methamphetamine
Background CTN Motivational Incentives Study • “Fishbowl” method offered drawings for prizes based on stimulant-negative urines; max earnings = $400 • Random assignment to usual care with or without incentives over 12-week evaluation • Prize-based incentives found effective for stimulant abusers enrolled in community drug abuse treatment • Improved retention in psychosocial counseling • Petry et al., Arch Gen Psychiat, Oct, 2005 • Reduced stimulant drug use in methadone maintenance • Peirce et al. Arch Gen Psychiat, Feb. 2006
Background • Regression analysis conducted to identify outcome predictors • Stimulant urine test result (pos/neg) at study entry emerged as strongest predictor of response to incentive procedure (R2 = .26)
Objective • Examine overall impact of intake stimulant urine test result on treatment outcome • Determine whether incentive effects differ for those who enter the study with stimulant positive vs negative urines
Methods • Grouping variable = first study urine stimulant positive vs negative • Stimulant = both cocaine & methamphetamine • Psychosocial counseling patients were new clinic intakes
Methods Outcome measures examined A) Study retention - time to last urine sample provided prior to 30-days with no contact B) Percent submitted samples stimulant negative twice weekly data collection Data analysis • Survival (A) • GEE (B) for main effects of group (stim pos/neg) and interaction of study treatments with intake urine
Retention 100 At study intake: Stimulant Negative (n = 306) Stimulant Positive (n = 108) 80 60 Percentage Retained 40 HR =1.71 (1.26-2.31) 20 0 0 1 10 12 2 3 4 5 6 7 8 9 11 Study Weeks
Retention Stimulant Negative (n = 306) Stimulant Positive (n = 108) 100 100 Incentive Incentive Usual Care Usual Care 80 80 60 60 Percentage Retained 40 40 20 20 HR = 1.19 ns HR = 1.86 (1.35-2.56) 0 0 2 4 6 8 10 12 12 8 2 4 6 10 Study Week Study Week
Stimulant Drug Use Percent submitted samples stimulant negative; missing urines considered missing Stimulant Negative (n = 306) Stimulant Positive (n = 108) 100 100 80 80 60 60 Percentage of Samples Stimulant Negative Incentive Incentive Usual Care Usual Care 40 40 20 20 0 0 4 2 6 12 2 4 6 8 10 8 10 12 Study Weeks Study Weeks
Stimulant Drug UsePercent submitted samples stimulant negative; missing urines considered positive Stimulant Negative (n = 306) Stimulant Positive (n = 108) 100 100 Incentive Incentive Usual Care Usual Care 80 80 60 60 OR = .95 (0.51-1.77) 40 40 20 20 OR =1.90 (1.4 - 2.6) 0 0 6 10 4 8 12 6 10 2 4 8 12 2 Study Week Study Week
Summary: Main Effect of Initial Urine Test Result • Stimulant positive at study entry confers a poor outcome prognosis • consistent with prior research (e.g Alterman et al., 1996, 1997; Ehrman et al., 2001; Sofuoglu et a., 2003)
Summary: Interaction of Incentives with Initial Urine Test Result • Improved retention in psychosocial counseling only for those stimulant negative at study start • Limited opportunity for stimulant positive to contact reinforcers?
Treatment Implications • Importance of initial urinalysis results in psychosocial counseling programs • Implications for treatment selection • Incentives for counseling patients entering tx stimulant negative • Special treatment (not abstinence incentives) for counseling patients entering tx stimulant positive
Acknowledgements • NIDA CTN for funding • MIEDAR study team for successful conduct of the multi-site study • Jessica Peirce for prediction analysis • Ken Kolodner and Rui Li for statistical support; Joe Harrison for graphics