The PRS were standardized (using the ‘scale’ function in R) before analysis. Mixed effect logistic regression models were used to test the association between PRS (at varying pT) and trajectory class membership (using pairwise comparisons between classes), the associations between peer use and trajectory class membership,between the PRS and peer use and also to test whether an interaction between PRS and peer cannabis use predicted trajectory membership, while accounting for all second order interaction terms (see42). All analyses included the family identifier and recruitment site as random effects (family nested within site).
