CONTINGENT REINFORCEMENT FOR CARBON MONOXIDE REDUCTION: WITHIN-SUBJECT EFFECTS OF PAY AMOUNT

The relationship between reinforcer amount and daytime smoking reduction in smokers offered money for reduced afternoon breath carbon monoxide (CO) levels was examined. Twenty-three hired regular smokers with average baseline CO levels of about 30 ppm were exposed in random order to five sliding scale payment schedules that changed daily or weekly. Money was available for afternoon CO readings between 0 and 21 ppm with pay amount inversely related to the absolute CO reading obtained. Maximum pay amount for readings below 7 ppm varied among $0, $1.50, $3, $6, and $12 per day. Contingent reinforcement promoted CO and daytime cigarette reduction within individuals with the amount of behavior change related to the amount of payment available. Average CO levels decreased from 30 to 15 ppm as a function of pay amount whereas self-reported daytime cigarettes decreased from 12 to 5 per day. Average minutes of cigarette abstinence prior to the afternoon study contact increased from 62 to 319 minutes as a function of pay amount, whereas the percentage of available money earned increased from 22% to 48%. Nontargeted evening cigarette use also decreased during periods of daytime smoking reduction. The orderly effects of this contingent reinforcement intervention on daytime smoking of regular smoker volunteers suggest that this is a sensitive model for continued evaluation of factors that influence smoking reduction and cessation.     

Effects of an Internet-based voucher reinforcement program for smoking abstinence: a feasibility study

The present study tested the feasibility of an Internet-based method to obtain objective evidence of smoking abstinence and to deliver vouchers for evidence of abstinence. Four heavy smokers participated in this 4-week study. Twice daily, participants made video recordings of themselves providing a breath carbon monoxide (CO) sample with a Web camera. The video was sent electronically to the smoking clinic. Participants could earn vouchers for gradual reductions in breath CO during an initial shaping condition, and then for achieving abstinence (CO < or = 4 ppm). Vouchers could be exchanged for merchandise at select Internet vendors. Relative to baseline conditions, participants substantially reduced their smoke intake, and 3 achieved sustained periods of abstinence. The study suggests that an Internet-based voucher reinforcement program is a feasible method to promote abstinence from cigarette smoking.     

Technology‐based contingency management and e‐cigarettes during the initial weeks of a smoking quit attempt

Contingency management (CM) interventions are among the most effective behavioral interventions for smoking. This study assessed the effects of CM and electronic cigarettes (ECs) on smoking reductions and abstinence for durations of 30‐36 days. Twelve participants were exposed to Baseline, EC alone, and EC + CM conditions. An internet‐based platform was used to monitor smoking via breath carbon monoxide (CO) and deliver CM for smoking abstinence (CO ≤4 ppm). A Bluetooth‐enabled EC monitored daily EC puffs. Abstinence rates were equivalent between EC (34.4%) and EC + CM (30.4%) conditions. Both conditions promoted smoking reductions. We observed an inverse correlation between smoking and EC puffs (r = ‐.62, p < .05). Results suggest the use of electronic cigarettes can promote smoking reductions and abstinence, and CM did not improve these outcomes. Larger magnitude consequences or tailoring EC characteristics (e.g., flavor) may have improved outcomes. Technology‐based methods to collect intensive, longitudinal measures of smoking and electronic cigarette use may be useful to characterize their environmental determinants.     

CONTINGENT PAYMENT PROCEDURES FOR SMOKING REDUCTION AND CESSATION

We assessed the ability of a combined contingent reinforcement and intensive monitoring procedure to promote and sustain temporary smoking cessation among 34 hired research volunteers, and the ability of a smoking reduction test to predict the subsequent initiation of abstinence. During the 5-day cutdown test, subjects were paid from $0 to $6 per day depending on the extent of reduction from baseline CO levels. During the abstinence test, breath samples were obtained three times daily and subjects were paid $4 for each CO reading ≤11 ppm. Sixty-eight percent of subjects initiated abstinence. Of the breath samples collected during the abstinence test (91% of scheduled samples), 96.5% were ≤11 ppm and 80.5% were ≤8 ppm. Subjects who earned more money during the cutdown test were more likely to abstain (r = ?0.51, p < .001). Contingent reinforcement and intensive monitoring procedures appear to have usefulness for analog studies of smoking reduction and cessation.     

CONTINGENCY MANAGEMENT PROMOTES SMOKING REDUCTIONS IN RESIDENTIAL SUBSTANCE ABUSE PATIENTS

Rates and consequences of cigarette smoking are more severe in substance abusers. In this 12‐week pilot study, residential substance abuse treatment patients received standard care for smoking cessation (n = 12) or prize contingency management (n = 12) for expired carbon monoxide (CO) tests ≤ 8 ppm and salivary cotinine < 10 ng/ml, which are indicative of smoking abstinence. Percentage of negative CO tests and the highest number of consecutive negative CO tests were greater in contingency management compared to standard care.     

mMotiv8: A smartphone‐based contingency management intervention to promote smoking cessation

Cigarette smoking is the leading preventable cause of death and illness in the United States. We tested the usability, acceptability, and efficacy of a smartphone‐based contingency management treatment to promote cessation. We used a nonconcurrent multiple‐baseline design. Participants (N = 14) provided breath carbon monoxide (CO) samples by using a CO meter that was connected to the user's smartphone. An app (mMotiv8) housed on participants' smartphones automatically captured pictures of the CO sampling procedure to validate the end user's identity, and it prompted submissions via a push message delivered to participants' smartphones. Participants earned a $10 incentive for daily abstinence, which was added to a reloadable debit card. Overall, 4% of the CO samples were negative during baseline, and 89% were negative during treatment. Self‐reported usability and acceptability were high, and 85% of the prompted samples were submitted. A smartphone intervention could be scalable and reduce the health consequences and costs associated with cigarette smoking, particularly in rural and low‐income populations.     

A Web-Based Contingency Management Program With Adolescent Smokers

The present study evaluated a new 30-day Web-based contingency management program for smoking abstinence with 4 daily-smoking adolescents. Participants made 3 daily video recordings of themselves giving breath carbon monoxide (CO) samples at home that were sent electronically to study personnel. Using a reversal design, participants could earn money for continued abstinence during the treatment phases (CO ≤ 5 ppm). All participants were compliant with the treatment (submitting 97.2% of samples), and all achieved prolonged abstinence from smoking.     

A Deposit Contract Method to Deliver Abstinence Reinforcement for Cigarette Smoking

Eight smokers were randomly assigned to a deposit contract ($50.00) or to a no-deposit group. Using a reversal design, participants could recoup their deposit (deposit group) or earn vouchers (no-deposit group) for smoking reductions and abstinence (breath carbon monoxide [CO] ≤ 4 parts per million) during treatment phases. Treatment was delivered via a novel Internet-based method to monitor smoking status. Although equivalent decreases in breath CO and abstinence were observed during treatment in both groups, $178.50 in vouchers were distributed to participants in the no-deposit group, whereas a small surplus remained in the deposit group. A deposit contract method may represent a cost-effective model to deliver abstinence reinforcement for cigarette smoking.     

MODIFYING HOW PEOPLE SMOKE: INSTRUCTIONAL CONTROL AND GENERALIZATION1

The modification of smoking behavior usually involves the target goal of total abstinence. However, many smokers are unable or unwilling to quit completely. An alternative is to teach people to smoke in ways that minimize the associated health risks. Such an approach would involve decreasing smoking rate, switching to “safer” tobacco products, and modifying the topography of consumption. Previous research has shown that topographical components of smoking behavior such as puff frequency, puff duration, cigarette duration, and amount smoked can be reliably measured and experimentally manipulated (Frederiksen, Miller, and Peterson, Addictive Behaviors, 1977, 2 , 55–61). Further, there is preliminary evidence from a single-subject experiment that topography can be changed in clinically relevant directions and that such changes can generalize to the smoker's natural environment (Frederiksen and Simon, Behavior Therapy, in press). To replicate and extend these findings, three single-subject experiments were conducted. In each experiment, verbal instructions to modify individual components of smoking topography were sequentially introduced using a multiple-baseline design across components. The components of puff frequency and puff duration were modified in three experiments. Cigarette duration was also modified in two experiments. Following the topography change phase, daily smoking rate was stabilized, using a behavioral contracting procedure (Frederiksen, Peterson, and Murphy, Addictive Behaviors, 1976, 1 , 193–196). Generalization was assessed during sessions in which no instructions were given (Subjects 1 and 3) and at six monthly followups (Subjects 2 and 3). For Subjects 2 and 3, data were also available on the amount of carbon monoxide (CO) uptake associated with the consumption of a cigarette (postcigarette CO-precigarette CO). This physiological measure is important because CO and its byproducts constitute a major health risk (Russell, Lancet, 1974, 1 , 254–258). Results showed that instructions were effective in modifying components of smoking topography. These changes generalized to sessions in which no instructions were given and across six months of followup. Daily smoking rate did not increase during topography change nor did smoking topography deteriorate when smoking rate was subsequently stabilized on a behavioral contract. Subjective ratings of smoking enjoyment decreased during topography change for two of three subjects but subsequently returned to baseline levels during followup. The observed topography changes were associated with a decrease in the amount of each cigarette smoked. Mean CO uptake was also reduced from baseline levels of 6.0 ppm and 8.0 ppm (Subjects 2 and 3, respectively) to followup levels of 3.3 ppm and 2.1 ppm. These results replicate and extend previous work and suggest that moderate or “controlled” smoking is an approach that deserves continued attention. The importance of assessing smoking topography and physiological variables, as well as directions for subsequent investigation, are discussed.     

Use of carbon monoxide breath validation in assessing exposure to cigarette smoke in a worksite population

Assessed the usefulness of carbon monoxide (CO) breath validation of self-reported smoking status in a large worksite population (N = 4,647). CO assessment was performed as part of a baseline survey procedure. CO levels differed substantially in relation to self-reported smoking status and amount smoked. Correcting for ambient exposure (estimated by mean CO levels among never smokers) produced more satisfactory results than uncorrected CO levels. Striking company differences were observed in mean CO exposures among self-reported never smokers. An unexpected finding was that 17.1% of current smokers reported smoking less than daily. Although the CO measure was excellent in detecting moderate and heavy smokers, it was inadequate in detecting occasional and light smokers. If detection of occasional or lighter smoking is critical to the purposes of the study, the more expensive (but more accurate) cotinine measure is preferred.     

Effects of internet-based voucher reinforcement and a transdermal nicotine patch on cigarette smoking

Nicotine replacement products are commonly used to promote smoking cessation, but alternative and complementary methods may increase cessation rates. The current experiment compared the short-term effects of a transdermal nicotine patch to voucher-based reinforcement of smoking abstinence on cigarette smoking. Fourteen heavy smokers (7 men and 7 women) completed the four 5-day phases of the study: baseline, patch treatment, voucher treatment, and return to baseline. The order of the two treatment phases was counterbalanced across participants. In the patch treatment condition, participants wore a 14-mg transdermal nicotine patch every day. In the voucher treatment condition, participants received vouchers contingent on abstinence from smoking, defined as producing carbon monoxide (CO) readings of < or =4 parts per million. Participants e-mailed two video clips per day showing them breathing into a CO monitor and the resulting CO reading to clinic staff. In the voucher treatment, 24% of samples were negative, and 5% of samples were negative in the patch treatment. Results suggest that contingent vouchers were more effective than transdermal nicotine patches in promoting abstinence.     

Carbon monoxide levels and rates of consumption after changing to low tar and nicotine cigarettes

Studies which have examined low tar and nicotine (LT/LN) cigarette smoking have failed, for the most part, to assess adequately the long-term effects of these cigarettes. Most studies have been short-term laboratory investigations of nicotine regulation. More practical strategies for changing to LT/LN cigarettes have largely been ignored. The present study examined long-term changes in smoking patterns following the gradual introduction of LT/LN cigarette smoking. Predicted increases in reported rates of consumption as well as carbon monoxide (CO) levels were not found for most smokers following changes to LT/LN cigarettes. Generally, smokers showed decreased rates of consumption, and a majority had lower CO levels at the end of treatment and during follow-up. Thus, LT/LN cigarette smoking would appear to be an alternative treatment goal for risk reduction in individuals who cannot stop smoking.     

Concurrent brief versus intensive smoking intervention during alcohol dependence treatment.

Alcohol dependent smokers (N=118) enrolled in an intensive outpatient substance abuse treatment program were randomized to a concurrent brief or intensive smoking cessation intervention. Brief treatment consisted of a 15-min counseling session with 5 min of follow-up. Intensive intervention consisted of three 1-hr counseling sessions plus 8 weeks of nicotine patch therapy. The cigarette abstinence rate, verified by breath carbon monoxide, was significantly higher for the intensive treatment group (27.5%) versus the rate for the brief treatment group (6.6%) at 1 month after the quit date but not at 6 months, when abstinence rates fell to 9.1% for the intensive treatment group and 2.1% for the brief treatment group. Smoking treatment assignment did not significantly impact alcohol outcomes. Although intensive smoking treatment was associated with higher rates of short-term tobacco abstinence, other, perhaps more intensive, smoking interventions are needed to produce lasting smoking cessation in alcohol dependent smokers.     

Women with diarrhoea-predominant irritable bowel syndrome show an increased pressure response to 35% carbon dioxide stress challenge

The responses to inhalation of 35% carbon dioxide (CO(2)) as a stressor were compared in female irritable bowel syndrome (IBS) patients and healthy controls to assess potential differences in cardiovascular, neuroendocrine and behavioural responses to stress. A total of 22 women (12 patients with ROME II defined diarrhoea-predominant IBS and 10 aged-matched controls) were challenged with a single vital capacity breath of 35% CO(2) (with 65% oxygen). Beat-to-beat blood pressure and heart rate were recorded prior to, during and after the inhalation. Serum cortisol concentration and behavioural ratings were measured pre- and post-inhalation. A typical pattern of responses to CO(2) was observed, characterised by a reduction in heart rate and increases in serum cortisol and anxiogenic symptoms; however, these responses did not differ between groups. Both groups also demonstrated an increase in systolic blood pressure; however, this response was significantly enhanced in IBS patients compared to healthy controls (P < 0.05). These findings demonstrate that females with diarrhoea-predominant IBS have an exaggerated pressor response to 35% CO(2) stress challenge, suggesting a more stress-responsive sympathetic nervous system.     

Visual masking and carbon monoxide toxicity.

Thresholds for letters were measured with and without a masking stimulus (presented either to the same eye as the letters or to the other eye) before and after exposure of smokers and nonsmokers to 500 ppm carbon monoxide (CO) in air for 1 hr. Identification of the unmasked letters was not degraded by CO but a number of thresholds of the masked letters were significantly affected among the smokers. The effects of the CO on binocular and interocular masking were similar. These results suggest that the first effects of CO toxicity are neither on the receptors nor central but on the transmission lines in between and that smokers are more susceptible than nonsmokers to short-term increases in the level of CO. The masking phenomenon, however, does not appear to be an unusually sensitive measure of CO toxicity.     

Effect of Concurrent Visual Feedback Frequency on Postural Control Learning in Adolescents

The purpose was to find better augmented visual feedback frequency (100% or 67%) for learning a balance task in adolescents. Thirty subjects were divided randomly into a control group, and 100% and 67% feedback groups. The three groups performed pretest (3 trials), practice (12 trials), posttest (3 trials) and retention (3 trials, 24 hours later). The reduced feedback group showed lower RMS in the posttest than in the pretest (p = 0.04). The control and reduced feedback groups showed significant lower median frequency in the posttest than in the pretest (p < 0.05). Both feedback groups showed lower values in retention than in the pretest (p < 0.05). Even when the effect of feedback frequency could not be detected in motor learning, 67% of the feedback was recommended for motor adaptation.     

Effects of biochemical validation of self-reported cigarette smoking on treatment success and on misreporting abstinence

Many investigators have reported that cigarette smokers who are trying to quit often falsely report being abstinent at the end of treatment. Unfortunately, much of the previous research designed to investigate this problem has been flawed, making the results difficult to interpret. We attempted to avoid these flaws and to investigate the measurement of alveolar carbon monoxide (CO) levels to validate self-reported smoking rates at the end of treatment. Participants in behavioral cessation clinics were randomly assigned to one of three conditions that varied in timing of exposure to information regarding CO measurement: at the beginning of treatment (demonstration of CO measurement, discussion of smoking effects on CO levels, and notification that individual CO levels would be measured at the conclusion of the clinic), at the end of treatment (demonstration, discussion, and notification of CO measurement prior to self-reports of smoking levels), or at the end of treatment (demonstration and discussion of CO measurement subsequent to self-reports of smoking levels). CO levels of all participants were measured at the end of treatment after they reported their current smoking levels. Only 16% of self-reports of abstinence were not verified by CO measurement. Smokers who observed the CO demonstration at the beginning of treatment were significantly more likely than the other two groups to achieve abstinence at the end of treatment and significantly less likely to misreport abstinence. Clinical and research implications of these results are discussed.     

Longitudinal Modeling of Adolescents' Activity Involvement, Problem Peer Associations, and Youth Smoking

Longitudinal associations among different types of organized activity involvement, problem peer associations, and cigarette smoking were examined in a sample of 1040 adolescents (mean age = 15.62 at baseline, 16.89 at 15-month assessment, 17.59 at 24 months) enriched for smoking experimentation (83% had tried smoking). A structural equation model tested longitudinal paths between three categories of involvement (team sports, school clubs and activities, and religious activities, measured at baseline and 15 months), problem peer associations (baseline and 15 months), and cigarette smoking behavior (baseline and 24 months). Multi-group analyses indicated pathways differed by type of activity and adolescent gender. Boys' baseline team sports and religious involvement predicted lower levels of smoking at 24 months via continued activity involvement at 15 months. Girls' involvement in school clubs and activities and religious activities indirectly predicted lower levels of smoking at 24 months via reduced exposure to problem peers at 15 months.     

Effects of normative feedback on motor learning are dependent on the frequency of knowledge of results

Studies on normative feedback have shown superior motor learning outcomes for individuals who believe that they are performing better than others through increased self-efficacy. Nevertheless, the effects of normative feedback were never dissociated from the knowledge of results (KR) provided to the learners which potentially interacts with self-efficacy as well. Thus, we investigated whether the effects of normative feedback on motor learning, associated with self-efficacy, would be dependent on the amount of KR provided. Fifty-six participants were randomly assigned to four experimental groups in terms of KR frequency (100% and 33%) and normative feedback (positive and negative). In the acquisition phase, all groups received the average KR of their performance at the end of each block of trials (True feedback) and a fake KR based on their own performance (but said to be from a group of participants who practiced the same task) (False Feedback). The False Feedback indicated better or worse performance of the participant in comparison to the fake group, depending on their experimental group. Retention tests were performed immediately and after 24 h from the acquisition phase. To measure self-efficacy, a questionnaire on participant's efficacy was applied before the first block, after each block of trials and before the retention tests. The results revealed superiority of positive normative feedback and 100% KR frequency, compared to negative normative feedback and 100% KR frequency in the 24h retention test. No difference was found between the groups with a frequency of 33% of KR (positive and negative). All groups increased self-efficacy during practice, but there was no difference between groups at any stage of the study. We conclude that the effects of normative feedback on motor learning are dependent on the KR frequency. However, they were not associated with self-efficacy.