Assessing the structure of the CAST (Cannabis Abuse Screening Test) in 13 European countries using multigroup analyses.

Our aims are to describe and explain the structure of the Cannabis Abuse Screening Test (CAST) across countries. Standard statistical analyses fail to describe and explain several variables simultaneously while taking account of the group structure of individuals. The 2011 European School Survey Project on Alcohol and other Drugs (ESPAD): 5204 last-year cannabis users aged 15-16 from 13 European countries. Multigroup principal component analysis (mgPCA) and multigroup partial least squares (mgPLS). MgPCA shows that the CAST has a two-dimensional structure (frequency of use/problems and non-recreational use/dependency symptoms). All the countries present a good concordance with the common structure, except Kosovo, Lichtenstein and Romania. MgPLS shows that three explanative variables (in a total of eight) are mainly related with the CAST (the frequencies of cannabis use in the last 12 months and in the last 30 days and the age at first cannabis use) while Kosovo, Lichtenstein and Romania also present specificities. The CAST structure appears stable in the 13 countries except for Kosovo, Lichtenstein and Romania that also show specific relationships between the CAST variables and their determinants.