Comparing participant estimated demand intensity on the cigarette Purchase Task to consumption when usual-brand cigarettes were provided free

Abstract

Accumulating evidence suggests that the hypothetical Cigarette Purchase Task (CPT), especially its demand Intensity index (i.e., estimated cigarettes participants would smoke if free), is associated with individual differences in smoking risk. Nevertheless, few studies have examined the extent to which hypothetical CPT demand Intensity may differ from consumption when participants are provided with free cigarettes. That topic is the overarching focus of the present study. Participants were 745 adult smokers with co-morbid psychiatric conditions or socioeconomic disadvantage. CPT was administered for usual-brand cigarettes prior to providing participants with seven days of their usual-brand cigarettes free of cost and consumption was recorded daily via an Interactive Voice Response (IVR) System. Demand Intensity was correlated with IVR smoking rate (rs 0.670–0.696, ps < 0.001) but estimates consistently exceeded IVR smoking rates by an average of 4.4 cigarettes per day (ps < 0.001). Importantly, both measures were comparably sensitive to discerning well-established differences in smoking risk, including greater cigarettes per day among men versus women (F(1,732) = 18.74, p < 0.001), those with versus without opioid-dependence (F(1,732) = 168.37, p < 0.001), younger versus older adults (F(2,730) = 32.93, p < 0.001), and those with lower versus greater educational attainment (F(1,732) = 38.26, p < 0.001). Overall, CPT demand Intensity appears to overestimate consumption rates relative to those observed when participants are provided with free cigarettes, but those deviations are systematic (i.e., consistent in magnitude and direction, Fs all <1.63; ps > 0.19 for all interactions with subgroups). This suggests that demand Intensity was sensitive to established group differences in smoking rate, supporting its utility as an important measure of addiction potential.