The effects of fixed versus escalating reinforcement schedules on smoking abstinence

Abstract

Studies indicate that when abstinence is initiated, escalating reinforcement schedules maintain continuous abstinence longer than fixed reinforcement schedules. However, these studies were conducted for shorter durations than most clinical trials and also resulted in larger reinforcer value for escalating participants during the 1st week of the experiment. We tested whether escalating reinforcement schedules maintained abstinence longer than fixed reinforcement schedules in a 12-week clinical trial. Smokers (146) were randomized to an escalating reinforcement schedule, a fixed reinforcement schedule, or a control condition. Escalating reinforcement participants received $5.00 for their first breath carbon monoxide (CO) sample <3 ppm, with a $0.50 increase for each consecutive sample. Fixed reinforcement participants received $19.75 for each breath CO sample <3 ppm. Control participants received payments only for delivering a breath CO sample. Similar proportions of escalating and fixed reinforcement participants met the breath CO criterion at least once. Escalating reinforcement participants maintained criterion breath CO levels longer than fixed reinforcement and control participants. Similar to previous short-term studies, escalating reinforcement schedules maintained longer durations of abstinence than fixed reinforcement schedules during a clinical trial.

Keywords: contingency management; differential reinforcement; nicotine; schedule of reinforcement; smoking cessation; tobacco.

Figure 1

Event records for escalating reinforcement, fixed reinforcement, and control participants. An individual participant constitutes one row on the ordinate. Visit number is shown on the abscissa. Black areas represent visits with breath CO samples <3 ppm. Gray areas represent visits with breath CO samples ≥3 ppm. White areas represent missed visits. Participants were first ordered by total number of criterion breath CO samples, then by number of consecutive breath CO samples, and finally by number of visits attended.

Figure 2

Total number of breath CO samples <3 ppm across each group. Each filled circle represents one participant. Gray area represents the mean percentage of breath CO samples <3 ppm for each group.

Figure 3

Proportion of participants who achieved at least a given number of consecutive breath CO samples <3 ppm across each group. Open triangles, filled circles, and gray triangles represent escalating reinforcement, fixed reinforcement, and control participants, respectively.