Abstinence Incentives for Methadone Maintained Stimulant Users: Outcomes for Those Testing Stimulant Positive vs Negative at Study Intake Maxine L. Stitzer Johns Hopkins Univ SOM National Drug Abuse Treatment Clinical Trials Network MIEDAR Study Team

Acknowledgements NIDA CTN for funding MIEDAR study team for successful conduct and reporting of the multi-site study Financial disclosures: none

Background Motivational incentives (e.g. prizes) promote behavior change (e.g. drug abstinence) Efficacy demonstrated across a number of abused drugs (alcohol, cannabis, cocaine, opiates,) Effectiveness demonstrated in large sample CTN multi-site study focusing on stimulant abusers in psychosocial counseling ( Petry et al., 2005 ) and methadone maintenance ( Peirce et al., 2006 ) treatment

Differential Response to Incentives Not everyone benefits from abstinence incentives In meth patients, response to incentives related to pre-study drug use (less use = better response) –(Preston et al., 1998; Silverman et al., 1998) Not known whether response is confined to lower severity users

Objective Examine overall impact of baseline stimulant use severity on treatment outcome using CTN data from the methadone maintained sample Determine whether incentive effects differ for those with higher and lower stimulant use severity

CTN Study Methods Methadone patients (N = 388) - stabilized w/ mean dose of 86mg and mean of 9 months in treatment at study entry Random assignment to usual care with or without incentives; 12-week evaluation “Fishbowl” incentive method used –Stimulant-negative urines (2/wk) earned prize drawings under escalating schedule –50% chance of earning a prize (range in value $1- $100; inverse relationship for value and probability)

Defining Drug Use Severity Regression analysis indicated that intake urine test result (stimulant pos/neg) was strongest predictor of outcomes among 20 variables examined (R 2 =.26) Present analysis stratifies on study intake urine test result (stim positive vs negative)

Participant Characteristics Stim PosStim Neg (N = 292) (N = 94) % female % white % > % employed % with drug dependence diagnosis stimulant alcohol cannabis 10 3

Follow-up Analysis Stratified analysis with 2 grouping variables –stimulant positive vs. negative urine sample at study intake –Incentive versus control condition Outcome measures: –Study retention (survival analysis) –Percent of stimulant-negative urine samples (General Estimating Equation; GEE)

Study Retention (effects ns)

Study Weeks Percentage of Samples Stimulant Negative Stimulant negative at intake n=94 Effect of Intake Urine Test Result on Overall Stimulant Use incentive and control groups collapsed OR = 8.7 CI = ) Stimulant Positive at intake n =292

Stimulant Negative (N = 94) Stimulant Positive (N = 292) Study Weeks Incentive Usual Care Incentive Effects in Those Stimulant Positive vs Negative at Intake Percentage of Samples Stimulant Negative OR = 2.27 ( ) OR = 1.84 ( )

Good outcome was associated with lower severity drug use Outcome: Number % Stimulant Neg Stim Neg Urines Sample Size At Entry

Summary Intake drug use severity is predictive of overall treatment outcome (negative urine ----> relatively better outcomes) Incentives reduced stimulant use during treatment independent of intake urine test result Similar OR’s suggest similar benefit magnitude despite different baseline rates of drug use

Discussion Results highlight prognostic importance of obtaining and attending to during-treatment urinalysis results Study adds to literature on generality of outcome in an abstinence incentive program Conclude incentives can be offered to all methadone maintained stimulant abusers to improve outcomes irrespective of use severity