Addictive Behaviors 2015;42: 144-147. [doi: 10.1016/j.addbeh.2014.11.020]
Thomas F. Northrup, PhD, Charles Green, PhD, N. Robrina Walker, PhD, Tracy L. Greer, PhD, Madhukar H. Trivedi, MD (all from University of Texas, TX Node).
The rapid rise in the number of methamphetamine users, relative to cocaine users, has brought the number of each to nearly equal levels, making research on similarities and differences across these groups a needed area of exploration. Craving is postulated to play a significant role in relapse for both users types, yet group differences on observed scale scores have been reported without first assessing the prerequisite measurement equivalence (invariance) of the items, which is essential for meaningful group comparisons. A brief, practical measure of cocaine craving exists (the 10-item Cocaine Craving Questionnaire-Brief [CCQ-Brief]), however, the data were collected over a decade ago at one site, excluded individuals under age 26 and individuals dependent on stimulants other than cocaine, and only 3% were female. For this study, the CCQ-Brief was adapted to broaden it to include "cocaine, methamphetamine or other stimulants," instead of just cocaine. The aim of this research was to psychometrically assess the resultant measure, the Stimulant Craving Questionnaire (STCQ).
Baseline data from stimulant users in residential treatment participating in CTN-0037 (Stimulant Reduction Intervention Using Dosed Exercise [STRIDE]) were used to assess the measurement invariance of the STCQ (N=301, n=177 cocaine, 124 methamphetamine). The unifactorial scale demonstrated measurement invariance across cocaine and methamphetamine users for factor loadings (metric), common residual covariances between item pairs, and item intercepts (scalar), as determined by fit indices. The latent mean, as well as 5 (out of 10) item means and the overall composite scale score, was significantly greater for methamphetamine users compared to cocaine users.
Conclusions: Results indicate that the STCQ is an invariant tool for the assessment of stimulant craving across the two most prevalent user types. Methamphetamine users had significantly higher levels of observed and latent craving than cocaine users, demonstrating a potentially meaningful difference in craving between users of these two stimulants. Future research will determine if treatments and statistical models need to account for craving variations across methamphetamine and cocaine users. (Article (Peer-Reviewed), PDF, English, 2016)
Keywords: Cocaine | Cocaine Craving Questionnaire (CCQ) | Craving | CTN platform/ancillary study | Methamphetamine | Screening and assessment instruments | Stimulant abuse | Stimulant Craving Questionnaire (STCQ) | Addictive Behaviors (journal)
Document No: 1236, PMID: 25462663., PMCID: PMC4272872.
Submitted by CTN Dissemination Librarians, 10/25/2016.