A Secondary Analysis of a Preliminary Contingency Management Intervention for Presurgical Cancer Patients: Evaluating Individual Participant Data

Introduction Contingency management (CM) interventions deliver monetary reinforcers contingent upon biochemically verified abstinence from smoking. CM has been found to be effective, however, individual participant, analyses are warranted to further elucidate how individual-level behavior patterns vary during the intervention period, both within and across treatment groups. Aims and Methods This is a secondary analysis of a randomized controlled pilot trial of presurgical cancer patients who smoke (RCT N = 40). All participants were current everyday smokers and were enrolled in cessation counseling, offered nicotine replacement therapy, and submitted breath CO testing 3 times per week for 2-5 weeks. Participants randomized to CM received monetary reinforcers for breath CO <= 6 ppm on an escalating schedule of reinforcement with a reset for positive samples. Sufficient breath CO data exist for 28 participants (CM = 14; monitoring only [MO] = 14). Effect size was calculated for differences in negative CO tests. Time to first negative test was tested using survival analysis. Fisher's exact test was used to assess relapse. Results The CM group achieved abstinence more quickly (p < .05), had a lower percentage of positive tests (h = 0.80), and experienced fewer lapses following abstinence (p = .00). While 11 of 14 participants in the CM group achieved and sustained abstinence by their third breath test, this was only true for 2 of the 14 MO participants. Conclusions Those in CM achieved abstinence quicker and with fewer lapses than those engaged in MO speaking to the efficacy of the schedule of financial reinforcement. This is particularly important within presurgical populations given the potential benefits to postoperative cardiovascular and wound infection risk. Implications While the efficacy of CM as an intervention is well established, this secondary analysis provides insight into the individual behavior patterns underlying successful abstinence. Those assigned to CM were not only more likely to achieve abstinence, but did so more quickly and with fewer instances of relapse. This is of particular importance to those scheduled for surgery where achieving abstinence as early as possible impacts on the risk of postoperative complications. CM interventions may be particularly well suited for critical windows in which timely and sustained abstinence is advantageous.