Titre : | Validation of self-reported cannabis dose and potency: an ecological study (2013) |
Auteurs : | P. VAN DER POL ; N. LIEBREGTS ; R. DE GRAAF ; D. J. KORF ; W. VAN DEN BRINK ; M. VAN LAAR |
Type de document : | Article : Périodique |
Dans : | Addiction (Vol.108, n°10, October 2013) |
Article en page(s) : | 1801-1808 |
Langues: | Anglais |
Discipline : | EPI (Epidémiologie / Epidemiology) |
Mots-clés : |
Thésaurus géographique PAYS-BASThésaurus mots-clés CANNABIS ; TETRAHYDROCANNABINOL ; AUTOEVALUATION ; FIABILITE ; VALIDITE ; CONSOMMATION ; ADULTE ; USAGE REGULIER |
Résumé : |
Aims: To assess the reliability and validity of self-reported cannabis dose and potency measures.
Design: Cross-sectional study comparing self-reports with objective measures of amount of cannabis and delta-9-tetrahydrocannabinol (THC) concentration. Setting: Ecological study with assessments at participants' homes or in a coffee shop. Participants: Young adult frequent cannabis users (n = 106) from the Dutch Cannabis Dependence (CanDep) study. Measurements: The objectively measured amount of cannabis per joint (dose in grams) was compared with self-reported estimates using a prompt card and average number of joints made from 1 g of cannabis. In addition, objectively assessed THC concentration in the participant's cannabis was compared with self-reported level of intoxication, subjective estimate of cannabis potency and price per gram of cannabis. Findings: Objective estimates of doses per joint (0.07-0.88 g/joint) and cannabis potency (1.1-24.7%) varied widely. Self-reported measures of dose were imprecise, but at group level, average dose per joint was estimated accurately with the number of joints made from 1 g [limit of agreement (LOA) = -0.02 g, 95% confidence interval (CI) = -0.29; 0.26], whereas the prompt card resulted in serious underestimation (LOA = 0.14 g, 95% CI = -0.10; 0.37). THC concentration in cannabis was associated with subjective potency ['average' 3.77% (P = 0.002) and '(very) strong' 5.13% more THC (P Conclusions: Self-report measures relating to cannabis use appear at best to be associated weakly with objective measures. Of the self-report measures, number of joints per gram, cannabis price and subjective potency have at least some validity. |
Domaine : | Drogues illicites / Illicit drugs |
Refs biblio. : | 28 |
Affiliation : | Trimbos Institute, Netherlands Institute of Mental Health and Addiction, Utrecht, the Netherlands |
Cote : | Abonnement |
Lien : | http://dx.doi.org/10.1111/add.12226 |
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