Identifying predictor variables of weight loss outcome: Implications for a stepped program and weight management

Abstract

Four variables were identified that predicted outcome for the minimal and moderate intensity weight control programs presented in sequence. Predictive models for pounds lost and percentage overweight lost were computed for both programs and follow-up and accounted for 33% to 62% of the variance. The predictor variable that contributed to the two programs and follow-up was success in losing weight previously. Greater rate of weight loss in the first five weeks contributed to the model for the minimal intensity program and for follow-up and total number of calories expended in nonroutine physical activity added to the model for the minimal intensity program. Marital dissatisfaction of subjects was a predictor for the moderate intensity program and follow-up. The findings have utility for a stepped program for weight and provide confirmation of variables noted as predictors in prior research. This study may help in the quest to identify consistent predictors of weight loss success.     

The effect of couples training and partner co-operativeness in the behavioral treatment of obesity

To evaluate the influence of spouse co-operativeness and couples training in the treatment of obesity, 29 obese men and women were assigned to three experimental conditions: (1) Co-operative spouse-couples training: subjects attended all meetings with spouses. Spouses were trained in modeling, monitoring, and reinforcement techniques; (2) Co-operative spouse-subject alone: subjects attended meetings alone even though their partners had agreed to become involved in treatment; (3) Non-cooperative spouse: subjects had spouses refusing to participate in the program, and attended sessions alone. At the 3-month and 6-month maintenance assessments. subjects in the spouse training condition lost significantly more weight than subjects in the other two conditions. Weight losses compared favorably to those of any controlled study with subjects in the couples training group averaging nearly 30 lbs lost after 8$\text{1}\text{2}$ months of treatment. In the absence of spouse training, subjects with co-operative spouses did no better than subjects with non-co-operative spouses. The findings suggest that spouse training may have a potent facilitative effect in weight reduction, and that this effect may promote long-term maintenance of weight loss.     

Spouse involvement and a possible long-term follow-up trap in weight loss

The present study was conducted to determine if husband attendance at treatment sessions and participation in behavioral contracting would produce greater weight losses than two other levels of spouse involvement. The three treatment groups investigated did not significantly differ at post-treatment but by 1-yr follow-up female Ss who attended treatment sessions alone and contracted with the counselor (HA) lost significantly more weight than women who attended sessions with their husbands and also contracted with the counselor (HNC). The Ss who attended sessions with their husbands and contracted with them (HC) did not significantly differ from Ss in the other two conditions. The total amount lost by Ss in the HA, HNC and HC conditions by 1-yr follow-up was 16.4, 4.4 and 15.5 lb, respectively. The study was also conducted to collect preliminary data about procedures Ss used during long-term follow-up to ascertain if weight losses during follow-up could be attributed to the behavioral weight-loss techniques learned during the treatment program. At all follow-up periods, many Ss reported using behavioral weight-loss techniques but 4 of the 36 Ss (11.1%) at 1-yr follow-up, 15 of the 23 (65.2%) and 24 of the 25 (96.0%) who responded, respectively, at 3- and 4-yr follow-up had used other weight-loss programs or methods. A possible confound for follow-up data was identified and suggestions for future research were presented.     

A comparison of techniques to affect sociometric status: A small step toward primary prevention in the classroom?

Interdependent tasks and role play were implemented as treatment conditions in three elementary classrooms (n=142) to affect the peer nominations of the subjects. Third to fifth grade subjects, 68 female and 74 male, received $\text{1}\text{2}$ hour per day of treatment or a control condition for two weeks. Sociometric measurements were obtained prior to the treatment, one week after, and six weeks after. Analysis of covariance was used to test the effectiveness of the treatments. One week following treatment, intersependent tasks was effective (p<.05) in causing subjects in all grades to pick formerly low status children. On the six weeks followup only fifth grade subjects showed the effects of interdependent tasks (p<.01). Several post hoc analyses were performed to investigate the mechanisms behind the change. The results suggest that interdependent tasks may be an effective strategy in raising the popularity of low status children if the treatment becomes an ongoing part of classroom routine. The implications for primary prevention are discussed.     

Peer-Enhanced Weight Management Treatment for Overweight Adolescents: Some Preliminary Findings

The purpose of this study was to evaluate the utility of adding a peer-based intervention (peer-based skills training [PBST]) to a traditional cognitive–behavioral weight management intervention for overweight adolescents. Sixteen adolescents between the ages of 13 and 16 years and between 30 and 80$percnt; overweight participated in a 16-week group-based weight management program with the addition of peer-based skills training. Adolescents and parents separately attended 60-min group sessions addressing diet, physical activity, and behavior modification techniques. In addition, adolescents attended a 90-min PBST session each week. Group activities included both mental and physical challenges that fostered development of trust, social skills, and self-confidence. Measures of height and weight, as well as questionnaires assessing self-concept, physical self-worth, and social functioning, were obtained prior to treatment, immediately following the 16-week intervention, and 6 months after completion of active treatment. Paired t tests revealed significant improvements over time in measures of physical self-worth, physical appearance and romantic appeal. Adolescents lost an average of 14.73 pounds from the start to end of treatment, and this was maintained at 6-month follow-up. These preliminary findings provide some support for the application of a novel peer-based program as an adjunctive treatment for adolescent weight management intervention.     

Evidence That a Very Brief Psychological Intervention Boosts Weight Loss in a Weight Loss Program

Reducing morbidity and mortality associated with being overweight is a crucial public health goal. The aim of the present research was to test the efficacy of a very brief psychological intervention (a volitional help sheet) that could be used as an adjunct to standard weight loss programs to support increased weight loss in an overweight sample. Seventy-two overweight participants currently participating in a weight loss program were randomly allocated to either an intervention (volitional help sheet) condition or a control (distracter task) condition. The main outcome measure was weight at 1-month follow-up. Participants in both conditions lost significant amounts of weight, but those in the intervention condition lost significantly more than those in the control condition (d = 0.66). The findings support the efficacy of the volitional help sheet to promote additional weight loss in an overweight sample engaged in a weight loss program. The volitional help sheet therefore represents a very brief, low-cost intervention that could be used to supplement ongoing weight-loss programs.     

Risperidone-induced polydipsia and polyphagia associated with galactorrhea, abdominal pain, and rapid weight gain in an adolescent Hispanic female

A 15-year-old Hispanic female was started on risperidone for new-onset psychosis. The patient responded well to the gradual dose increase but developed rapid weight gain secondary to polydipsia and polyphagia. She also began complaining of nipple discharge and griping abdominal pain on the left lower quadrant by the third week of treatment. Her prolactin level escalated to three times normal with a weight gain of 12 pounds in 16 days. Risperidone was switched to another antipsychotic. Her prolactin level then dropped to a normal level within 7 days and she lost 7 pounds in the next 2 weeks. Her abdominal pain, galactorrhea, polydipsia, and polyphagia subsided within the first few days of the cessation of risperdione.     

Self-directed weight control through eating and exercise

A weight control program using a written contract and other self-control behavior modification techniques for changing eating habits was compared with a similar program concentrating on both eating and exercise behavior and with an attention-placebo control condition. Participants in all three programs lost weight during the 12 week program, with no significant differences between groups. A seven-month follow-up revealed that Ss in the two behavior modification groups lost more than those in the control group and that those in the eating plus exercise group lost more than those in the group dealing only with eating behavior.     

A seven year follow-up of treating rumination with dietary satiation

”Fred“, a man with profound mental retardation who was 24 years old at the beginning of this study, was referred for treatment of rumination. A number of minimally restrictive interventions, including administration of Zantac, extra fluids, and delivery of peanut butter after meals, had been used without success. In April of 1989 Fred began a satiation diet with ad libitum access to starchy foods or to fruits and vegetables, in addition to his regular meals. His baseline weight was 82 pounds and he ruminated during 58% of 10 s intervals measured during 20 min post-meal observations. During the first month of the satiation diet, Fred's ruminating declined to 6% of measured intervals, he consumed a mean of 163 fluid ounces of extra food per day, and his weight increased to 90 pounds. After 4 months' treatment, Fred's ruminating had declined to zero, his food consumption had stabilized at approximately 65 extra ounces of food per day, and his weight had stabilized at about 120 pounds. Starting in August 1990, in an effort to minimize weight gain, extra food was limited to 50% of Fred's ad libitum food consumption (averaged over the previous 6 weeks). Fred's weight gradually declined to about 100 pounds with zero rumination over the next two years. In August 1992 Fred's ruminating accelerated to 17% of intervals and he was again offered ad libitum food access. Over the next 7 months, rumination declined to zero and his weight increased slightly to about 105 pounds. This study shows that rumination that had not responded to less restrictive procedures was suppressed for 7 years via dietary satiation. Although dietary satiation is not without some risk, Fred has suffered no adverse effects from the procedure, other than gaining approximately one-third of his baseline weight. © 1997 John Wiley & Sons, Ltd.     

The effects of a cooperation contingency on behavior in a continuous three-person environment

Five groups of three subjects resided for 10 or 15 days within a continuously programmed environment. Subjects followed a programmatic arrangement of required and optional private and social activities that determined the individual and group baseline behaviors into which experimental operations were introduced and withdrawn. A cooperation condition was in effect when all three subjects were required to select simultaneous access to a group area before it became available for use. A noncooperation condition was in effect when access to a group area could be selected by individual subjects, without regard to the other subjects' selections. For all groups, the effects of these two conditions on individual and group behaviors were investigated in reversal designs where several successive days occurred under each condition. Groups 1, 4, and 5 had the noncooperation condition interposed between cooperation conditions. Groups 2 and 3 had the cooperation condition interposed between noncooperation conditions. Durations of triadic activities, per cent of time in triadic activities, intercom use, and intersubject program synchronization were greater during cooperation conditions than during noncooperation conditions. These data show that a cooperation contingency within the behavioral program affected both social behavior and the collateral individual behavior necessary to execute the cooperation response.     

Cross‐Cultural Examination of the Tripartite Model in Adults

Abstract

Operant conditioning was applied to a total of 32 female anorexia nervosa patients in order to restore their normal weight. A comparative study was carried out on two groups of 16 patients each, who were treated with two different therapeutic procedures. The group having informational feedback, more flexible contacts with their family and a special psychomotor program (Group B), achieved a greater rate of weight gain compared to the other group (Group A), with an average of 1.75 versus 1.30 per week. The differences in weight evolution and problems during treatment are discussed. The fact that the study only is a short-term one concerning a limited aspect of the treatment of anorexia nervosa, and also the need for further follow-up research is strongly emphasized.     

Preventing weight gain in adults: a pound of prevention

This study evaluated the feasibility and effectiveness of a program for weight gain prevention in normal-weight adults. Two hundred nineteen participants were randomized to either weight gain prevention treatment or no treatment for a period of 12 months. Those in the treatment group received monthly newsletters relating to weight management, participated in a financial incentive system, and were offered an optional four-session education course in the sixth month of the program. Results demonstrated high interest in weight gain prevention among individuals who were not objectively overweight. Participation, as measured by return of postcards sent with each newsletter, was approximately 75%. Results after 1 year showed a net weight loss in the group receiving the program of 1.8 lb compared to those in the control group. Eighty-two percent of program participants maintained or lost weight, compared to 56% of the control group. It is concluded that programs for weight gain prevention are feasible in adults and may be more effective than weight loss treatment programs in addressing the problem of community-wide obesity.     

Delivering Acceptance and Commitment Therapy for Weight Self-Stigma Through Guided Self-Help: Results From an Open Pilot Trial

Weight self-stigma is a promising target for innovative interventions seeking to improve outcomes among overweight/obese individuals. Preliminary research suggests acceptance and commitment therapy (ACT) may be an effective approach for reducing weight self-stigma, but a guided self-help version of this intervention may improve broad dissemination. This pilot open trial sought to evaluate the potential acceptability and efficacy of a guided self-help ACT intervention, included coaching and a self-help book, with a sample of 13 overweight/obese individuals high in weight self-stigma. Results indicated a high degree of program engagement (77% completed the intervention) and satisfaction. Participants improved on outcomes over time including weight self-stigma, emotional eating, weight management behaviors, health-related quality of life, and depression. Although not a directly targeted outcome, participants improved on objectively measured weight, with an average of 4.18 pounds lost over 7 weeks, but did not improve on self-reported weight at 3-month follow-up. Processes of change improved over time, including psychological inflexibility, valued action and reasons to lose weight. Coaching effects indicated greater retention and improvements over time with one coach vs. the other, suggesting characteristics of coaching can affect outcomes. Overall, these results provide preliminary support for the acceptability and efficacy of a guided self-help ACT program for weight self-stigma. Implications of these results and how to address clinical challenges with guided self-help are discussed.     

THE EFFECT OF A TOKEN ECONOMY ON DIETARY COMPLIANCE FOR CHILDREN ON HEMODIALYSIS

Adherence to dietary restrictions is a recurring problem for children on hemodialysis. The effect of behavior modification in maintaining dietary control is reported for four patients aged 11 to 18 years. Weight gain, potassium level, and blood urea nitrogen were utilized as criteria measures. A token reinforcement program implemented by the hemodialysis team resulted in significant changes in the dietary pattern of the children. The average weight gain between dialysis sessions for the four subjects during treatment was reduced by 45% and the degree of weight fluctuation was lessened. Potassium levels and BUN were controlled to their appropriate level for subjects who initially exceeded the criterion level. With the withdrawal of weight gain from the contingency system, increase of weight gain between dialysis sessions was noted for all subjects.     

Encoding and retrieval effects of dual sensory-semantic cues

This experiment was designed to explore the relative effects of dual and embedded sensory-semantic retrieval cues (e.g.,GLAMOUR GIRL). Cues and targets shared both first-letter and associative features, only first-letter features, or only associative features. The cues were presented during the single test trial or they were presented during the single study trial and again at test. Finally, subjects in the dual-cue condition were or were not told about the addition of the first-letter contingency. The results indicated that dual were superior to single cues with each feature contributing independently and additively to recall. This dual facilitation was obtained when the cues were shown only at test or during both study and test and regardless of whether or not the subjects were explicitly aware of the additional sensory contingency. These findings were expected and explained by the assumptions of the coding-access-recognition model     

AN EXPERIMENTAL COMPARISON OF A CONTINGENCY MANAGED COURSE WITH LARGE LECTURE METHOD1

Contingency management procedures resembling the Personalized System of Instruction (PSI) were compared with a conventional lecture method in teaching an introductory psychology course. The use of a within-subjects design in which half of the students experienced both teaching conditions made it possible to examine the reliability of test-score differences over time when subjects were balanced over conditions. In the contingency management course, material was broken down into 14 small units, each unit covering about 30 pages of text. Students were assigned to an undergraduate teaching assistant who was encouraged to develop a close working relationship with each of his/her 13 assigned students. Specifically, this meant that the assistant was to call each student by his/her first name, show an interest in the student's quiz performance, help the student understand difficult concepts, and discuss various topics of interest to the student. Each week, the teaching assistant administered up to four different 10-item multiple-choice quizzes over the week's chapter. A modified “Doomsday Contingency” required each student either to achieve a score of 80% on one of the four quizzes or drop the course. Most students passed the quiz during the first session of the week; those not passing were tutored on special areas of weakness. No student was actually forced to leave the course under the Doomsday Contingency. Although quizzes were administered on a group basis, they were scored individually while the student stood near by. In addition to the weekly quiz assignment, students under the contingency management procedures were asked to attend one lecture per week. The contingency management method departed from traditional PSI in that (1) self pacing was minimal, such that students were required to master one unit per week or drop the course, (2) teaching assistants met with students in small groups, and usually gave individual tutoring only to those students who did not pass the quiz on the first attempt, and (3) students were asked to attend one lecture per week. However, it was similar to PSI in that small units of subject matter were assigned and unit mastery was assessed through use of undergraduate assistants who delivered immediate feedback. Students in the conventional lecture group attended three 50-min lectures each week; two of these lectures followed textbook material closely, while the third, which was attended by all students, concerned material only indirectly related to the text. As a result, students in both conditions were exposed to essentially identical material. Students in the lecture condition could also obtain copies of the unit quizzes, although few did so. Course grades were determined by scores on two 45-item multiple-choice hourly exams, each covering half of the semester material (each worth 25%), and by a 90-item final exam over the entire course (worth 50%). These measures also served as the dependent variables. The experimental design employed a crossover technique in which one fourth of the students began with the contingency management method and then switched to lecture method at midsemester, while another fourth began with the lecture method and switched to contingency management. The other students stayed in the same condition throughout the semester, half under contingency management and half under the lecture method. On the last day of class, all students filled out an extensive questionnaire that assessed their opinions and attitudes about the teaching techniques. In addition to allowing for assessment of any progressive effects that the contingency management procedures might have had over time, the crossover design also permitted students to make meaningful comparisons of the two teaching methods, since half of the students experienced both methods in the same course. Although average test performance was only slightly higher under the contingency management condition, this difference occurred on each exam and was statistically reliable in each case. Further, the method did not interact with time, as it produced about a three-item advantage per half semester. On each of the three exams, teaching method accounted for between 5 and 8% of the total variance in test scores. Finally, attitude measures indicated that students experiencing half a semester of the contingency management procedures preferred them to the lecture technique, but that only those students with a full semester of contingency management rated the course significantly better than students in the full semester lecture course.     

Effects of preexisting and manipulated self-efficacy on weight loss in a self-control program

The present study was designed to investigate the effects of self-efficacy on weight loss utilizing self-control techniques. Subjects high and low in preexisting self-efficacy were randomly assigned to high or low manipulated self-efficacy groups in a 2 × 2 (preexisting self-efficacy × manipulated self-efficacy) factorial design. Preexisting self-efficacy was assessed using procedures employed byBandura and Adams (1977, Cognitive Therapy and Research, 1, 287–308). Selfefficacy was manipulated by having subjects attribute successful task performance to a previously unrecognized capacity for self-control. Subjects met in groups once a week for a total of 8 weeks and received a comprehensive weight control program within the context of self-control. Results indicated significant manipulated and preexisting × trials interactions with both the high manipulated and preexisting self-efficacy groups losing more weight over the 8 weeks than the low preexisting and manipulated groups. In addition, locus of control was predictive of weight loss, with internals tending to lose more weight than externals. Results are discussed in terms of Bandura's (1977, Psychological Review, 84, 191–215) theory of self-efficacy.     

A TOKEN REINFORCEMENT PROGRAM IN A PUBLIC JUNIOR-HIGH SCHOOL1

In recent years, the technology of contingency management has been shown to be of increasing value in regular classrooms and public-school systems with both groups and individual pupils (Ayllon and Roberts, Journal of Applied Behavior Analysis, 1974, 7 , 71–76; Glynn and Thomas, Journal of Applied Behavior Analysis, 1974, 7 , 299–306; Lovitt and Curtiss, Journal of Applied Behavior Analysis, 1969, 2 , 49–53; Lovitt and Smith, Exceptional Children, 1974, 40 , 357–358; Medland and Stachnik, Journal of Applied Behavior Analysis, 1972, 5 , 45–51). In addition, established procedures are being systematically replicated across grade levels and differing subject-matter areas. A series of studies initiated by O'Leary and Becker (Exceptional Children, 1967, 33 , 637–642) form the basis for the present investigation. The token reinforcement program described by O'Leary and Becker (Exceptional Children, 1967, 33 , 637–642) was managed by the teacher of an adjustment class and involved 9-yr-old children described as emotionally disturbed. An elaborate replication of the 1967 O'Leary and Becker study conducted by O'Leary, Becker, Evans, and Saudargas (Journal of Applied Behavior Analysis, 1969, 2 , 3–31) with a grade-two class introduced several variables to examine their separate effects. The authors specified their treatment levels as baseline, classroom rules, educational structure, teacher praise and ignore, token I, withdrawal, token II, and follow-up. The present research modified the general design of O'Leary et al., (Journal of Applied Behavior Analysis, 1969, 2 , 3–31) to study how to maintain treatment effects. In the modification, rules were eliminated as a treatment variable because they are frequently associated with aversive practices in the school system, and it was deemed desirable to have mainly a positive orientation. A second difference was that the present subjects were grade-nine pupils functioning in the regular public-school system. The six students were older (average age = 16.2) and well behind their peers in achievement. They were considered behavior problems and as potential dropouts by teachers and counsellors. They were not considered to be emotionally disturbed. Finally, procedures designed to maintain behavior change generated by the token system were added. The operant level of unacceptable classroom behavior was obtained for six students receiving an individualized program of instruction in mathematics and science in a nonacademic grade-nine class in a public junior secondary school. Initially, two conditions (educational structure and praising appropriate behavior while ignoring inappropriate behavior) were introduced successively. Both procedures reduced inappropriate behavior slightly. When a token system, using backup reinforcers readily available in the school, was introduced in conjunction with the initial two conditions, inappropriate responses declined dramatically in all subjects. Withdrawal of the token program for a three-week period, leaving educational structure and praising and ignoring in effect, increased inappropriate behavior in five of the six subjects. The token program was then re-introduced in conjunction with contingency contracts. The result was a decline of inappropriate behavior below the mean of the first token condition for all subjects. Tokens were thinned and finally removed toward the end of this condition, leaving teacher praise and attention and the contract system in effect. Data obtained during a four-week followup indicated that the low level of inappropriate behavior was maintained in all subjects. This extension of the O'Leary et al., (Journal of Applied Behavior Analysis, 1969, 2 , 3–31) program, designed and implemented by the regular teacher, demonstrates that these procedures may be highly effective within the constraints found in an ordinary classroom in the junior secondary school.     

SHORT- AND LONG-TERM EFFECTS OF CONTINGENCY MANAGED INSTRUCTION ON LOW,MEDIUM, AND HIGH GPA STUDENTS1

Undergraduate students had been assigned to a contingency managed course or a conventional lecture course (Du Nann and Fernald, Journal of Applied Behavior Analysis, 1976, 9 , 373–374). Two years later, some 35% (N = 86) of the original classes responded to a letter offering them $2.00 to participate in a study of their educational experiences. These students completed a multiple-choice test on material from the course, and answered questions about activities and attitudes that might have been affected by the experience in Introductory Psychology. In the contingency management course 2 yr past, students were tested each week on a chapter of textbook material with 10-item multiple-choice quizzes. The course employed a modified “Doomsday Contingency”, requiring each student to achieve 80% mastery on one of the four weekly quizzes or drop the course. Quizzes were given in small groups and scored individually, while the student stood near, by an undergraduate proctor assigned to that group. The proctor was asked to show interest in the students' quiz performances, help clear up difficult areas, and develop a friendly working relationship with each student. While many students passed the quiz on the first attempt, others were given individual tutoring, so that no one was in fact forced to drop the course. In addition to the weekly quiz assignment, students in the contingency managed group were asked to attend one lecture each week. While the contingency management course procedures had much in common with PSI (Keller, Journal of Applied Behavior Analysis, 1968, 1 , 79–89), several departures made them unique. First, self-pacing was curtailed because students were required to master one unit per week or drop the course. Second, proctors met with students in small groups, usually giving individual tutoring only to those students who did not pass the quiz on the first attempt. Finally, students were asked to attend one lecture per week. Students in the conventional lecture group were not asked to pass weekly quizzes, but instead attended three 50-min lectures each week. Two of these lectures followed the textbook material closely, while the third, which was also attended by students from the contingency management course, covered material only indirectly related to the text. This partition of lecture content allowed material to be similar across the two instructional groups. Although students in the lecture condition were told they could obtain copies of the quizzes, few of them did so. Course grades were determined by scores on two 45-item multiple-choice hourly exams, each covering half the semester material (each worth 25%), and by a 90-item final exam, which served as a measure of short-term retention. Before analyzing the follow-up data, several characteristics of the returning students were compared to determine the comparability of the sample from the two original classes. Most important, both attrition and the current mean GPAs of students from the two classes were very similar. These considerations, and others, suggested there was no systematic sampling bias to confound comparisons of student performance. A 2 (contingency management versus traditional lecture) by 3 (high, medium, and low GPA) analysis of variance was computed on the course final-exam scores and the follow-up measures. Instructional procedure and GPA interacted on the final exam such that low and medium GPA students performed significantly better under contingency management, but there was no significant effect of instructional procedure with high GPA students. On the 2-yr retention measures, students from the contingency management course performed significantly (p < 0.01) better on items drawn from quizzes used in their original course, and marginally better (p < 0.10) on items drawn from the final exams, but no interactions with GPA appeared. Furthermore, instructional method produced no significant main effects or interaction with how many students became majors or minors in psychology, how many psychology courses were later taken, how many books in psychology were reported to have been read, or on students' evaluation of the interest and importance of psychology.     

Randomized Trial Comparing Two Treatment Strategies Using Prize-Based Reinforcement of Abstinence in Cocaine and Opiate Users

We compared two strategies of prize-based contingency management (CM) in methadone-maintained outpatients. Urine was tested thrice weekly for 5 weeks pre-CM, 12 weeks CM, and 8 weeks post-CM. Participants were randomly assigned to a cocaine contingency (four prize draws for each cocaine-negative urine, N  =  29) or an opiate-cocaine contingency (one draw for each urine negative for opiates or cocaine, four draws if negative for both, N  =  38). There were no group differences in cocaine abstinence during CM or post-CM and no differences in opiate abstinence during CM. Opiate abstinence was greater in the opiate-cocaine group post-CM, and heroin craving was reduced in this group during and post-CM. Draws earned per cocaine-negative urine (four vs. one) did not affect cocaine use.