Characterizing the reinforcing value of tobacco using a cigarette purchase task: An item response theory approach

Concurrent validity of the marijuana purchase task: a meta-analysis of trait-level cannabis demand and cannabis involvement

BACKGROUND AND AIMS

The Marijuana Purchase Task (MPT) is increasingly used to measure cannabis reinforcing value and has potential use for cannabis etiological and regulatory research. This meta-analysis sought to evaluate for the first time the MPT's concurrent validity in relation to cannabis involvement.

METHODS

Electronic databases and pre-print repositories were searched for MPT studies that examined the cross-sectional relationship between frequency and quantity of cannabis use, problems, dependence, and five MPT indicators: intensity (i.e. unrestricted consumption), Omax (i.e. maximum consumption), Pmax (i.e. price at which demand becomes elastic), breakpoint (i.e. first price at which consumption ceases), and elasticity (i.e. sensitivity to rising costs). Random effects meta-analyses of cross-sectional effect sizes were conducted, with Q tests for examining differences by cannabis variables, meta-regression to test quantitative moderators, and publication bias assessment. Moderators included sex, number of MPT prices, variable transformations, and year of publication. Populations included community and clinical samples.

RESULTS

The searches yielded 14 studies (n = 4077, median % females: 44.8%: weighted average age = 29.08 [SD = 6.82]), published between 2015 and 2022. Intensity, Omax , and elasticity showed the most robust concurrent validity (|r's| = 0.147-325, ps < 0.014) with the largest significant effect sizes for quantity (|r| intensity = 0.325) and cannabis dependence (|r| Omax  = 0.320, |r| intensity = 0.305, |r| elasticity = 0.303). Higher proportion of males was associated with increased estimates for elasticity-quantity and Pmax -problems. Higher number of MPT prices significantly altered magnitude of effects sizes for Pmax and problems, suggesting biased estimations if excessively low prices are considered. Methodological quality was generally good, and minimal evidence of publication bias was observed.

CONCLUSIONS

The marijuana purchase task presents adequate concurrent validity to measure cannabis demand, most robustly for intensity, Omax , and elasticity. Moderating effects by sex suggest potentially meaningful sex differences in the reinforcing value of cannabis.

No evidence of the clinical utility of single-item breakpoint to inform on tobacco demand in persons with substance use disorders

RATIONALE

Behavioral economics has shown that single-item demand indicators are promising for capturing crucial aspects of nicotine reinforcement. It is suggested that brief breakpoint measures perform comparably to full-length demand indices in characterizing nicotine dependence; however, there have been no thorough assessments of their validity in clinical settings.

OBJECTIVES

This study aimed to assess the validity and accuracy of a single-item breakpoint in informing on tobacco demand.

METHODS

The sample consisted of 88 treatment-seeking smokers (% males = 70.5%) enrolled in substance use treatment. Participants provided data on smoking characteristics and completed the Fagerström Test for Nicotine Dependence, a single-item breakpoint measure and a 14-item cigarette purchase task (CPT). Hierarchical regressions were performed to compare the predictive capability of a single-item breakpoint and full-length tobacco demand indicators in determining nicotine addiction severity.

RESULTS

The single-item breakpoint was significantly correlated with all indices stemmed from the CPT and both latent factors (all r values = .250-.368). Neither the brief breakpoint nor the full-length breakpoint significantly predicted nicotine dependence. After controlling for sex and smoking variables, factor 2 [β = .565, p < .001] and its observed variables Omax [β = .279, p = .006], 1/elasticity [β = .340, p = .001], and intensity [β = .551, p < .001], robustly predicted nicotine dependence severity.

CONCLUSIONS

Our findings do not support the validity of single-item breakpoint measures for characterizing nicotine dependence in substance users. In a bid to foster translational research, brief demand measures capturing Omax, intensity, and elasticity should be developed.

No evidence of differences in smoking levels, nicotine dependence, carbon monoxide or motivational indices between cigarette smokers and cigarette + e-cigarette dual users in two samples

Concurrent use of electronic cigarettes (e-cigarettes) as an alternative source of nicotine may lead to lower smoke exposure, tobacco addiction and reinforcing value of conventional combustible cigarettes. In two different cohorts, we characterized smokers, dual cigarette/e-cigarette users, and e-cigarette-only users in terms of sociodemographic, motives and patterns of e-cigarette use. Differences in smoking-related characteristics and reinforcing value of cigarettes between smokers and e-cigarette dual users were also examined. Two cohorts comprising 339 community adults [Sample 1; aged 18-65] and 293 young adult binge drinkers [Sample 2; aged 19-24] were recruited in Hamilton, Ontario. All participants provided expired carbon monoxide (CO) samples and completed an assessment battery including the Fagerström Test of Nicotine Dependence (FTND), the Wisconsin Inventory of Smoking Dependence Motives (WISDM), and the Cigarette Purchase Task (CPT). In both samples, smoking rate, CO level, FTND, WISDM, and CPT responses did not significantly differ between smokers and dual users. Compared to e-cigarette-only individuals, dual users from the two cohorts reported a greater use of e-cigarettes for quitting smoking, but dual product consumers exhibited no significant differences in motivation for change relative to combustible-only smokers. Relative to smokers, e-cigarette dual users did not show lower levels of smoking, lower severity of cigarette addiction and reinforcing value of cigarettes in these samples. These findings suggest that concurrent e-cigarette use does not affect combustible tobacco use or motivation, or reduce its harms.

Behavioral economic measurement of cigarette demand: A descriptive review of published approaches to the cigarette purchase task

The cigarette purchase task (CPT) is a behavioral economic method for assessing demand for cigarettes. Growing interest in behavioral correlates of tobacco use in clinical and general populations as well as empirical efforts to inform policy has seen an increase in published articles employing the CPT. Accordingly, an examination of the published methods and procedures for obtaining these behavioral economic metrics is timely. The purpose of this investigation was to provide a review of published approaches to using the CPT. We searched specific Boolean operators (["behavioral economic" AND "purchase task"] OR ["demand" AND "cigarette"]) and identified 49 empirical articles published through the year 2018 that reported administering a CPT. Articles were coded for participant characteristics (e.g., sample size, population type, age), CPT task structure (e.g., price framing, number and sequence of prices; vignettes, contextual factors), and data analytic approach (e.g., method of generating indices of cigarette demand). Results of this review indicate no standard approach to administering the CPT and underscore the need for replicability of these behavioral economic measures for the purpose of guiding clinical and policy decisions. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Validation of an E-cigarette Purchase Task in Advanced Generation Device Users

INTRODUCTION

Behavioral economic purchase tasks are used to estimate the reinforcing value of drugs by asking participants how much they would purchase across a range of increasing prices. We sought to validate such a task for e-cigarettes in experienced users of advanced generation, tank-style devices.

METHODS

Dual users of cigarettes and e-cigarettes (N = 54) and exclusive e-cigarette users (N = 59) attended one session during which they completed assessments including two versions of the E-cigarette Purchase Task: one that asked how many puffs of their e-cigarette they would purchase in 24 hours at varying prices and one that asked how many mLs of e-liquid they would purchase. We correlated purchase task outcomes with other measures of e-cigarette use. We also compared the tasks across dual and exclusive users.

RESULTS

Indices derived from the mLs-based task were more likely to be correlated with self-reported use rates, e-cigarette dependence, and cotinine levels than the puffs-based task. Exclusive users showed greater demand on than dual users only on the mLs version when using an F-test comparison method, while multivariate analysis of variance (MANOVA) results showed that dual users showed greater demand only on the puffs task.

CONCLUSIONS

Results indicate that the mLs version had greater validity than the puffs version in terms of clinical indices. Dual users may still be on a trajectory to fully switching to e-cigarettes; thus, puffs as a measure may be more intuitive, as this measure is shared by cigarettes and e-cigarettes. For exclusive users, the unit they purchase their e-liquid in may be the most relevant unit and better capture their demand for that product.

IMPLICATIONS

Behavioral economic purchase tasks have been widely used to understand nicotine use. We have developed two versions of a purchase task for e-cigarette use and compared the two versions in users of advanced generation e-cigarette devices. We found that the mLs version of the task better-reflected use patterns relative to a puffs version, which suggests that participants struggle to place monetary value on a unit of consumption (ie, puffs). Validated measures of e-cigarette reinforcement will be important as researchers and regulators determine which features of these products contribute to reinforcing efficacy.