highly significantP < 2.2 × 10 –16
eTable 3 shows the results in a model quadratic in time and confirms highly significant differences in cannabis use by ethnicity (from β estimate = 1.67 (95% CI 1.45–1.89), P < 2.2 × 10 –16 ; quadratic superior to linear model, ANOVA F = 2.147, df = 13, P = 0.019). eFigure 5 shows that high intensity cannabis use is falling amongst teenagers, but rising in older age groups. eFigure 6 confirms these age-dependent trends in the first trimester of pregnancy which shows more cannabis use than later trimesters. eFigure 7 has been drawn from CDC birth data and confirms the trend of childbirth to be occurring at older maternal ages.