1. Concurrent validity of the marijuana purchase task: a meta-analysis of trait-level cannabis demand and cannabis involvement
- Author
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González-Roz, Alba, Martínez-Loredo, Víctor, Aston, Elizabeth R., Metrik, Jane, Murphy, James, Balodis, Iris, Secades-Villa, Roberto, Belisario, Kyla, and MacKillop, James
- Abstract
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
- Published
- 2023