a decreasing trendP = 0.001
borderline significanceP = 0.09
In contrast, the first-time offense rate of methamphetamine had an increasing trend (0.66 per 100,000 per year; P = 0.09, borderline significance) and that of ecstasy had a decreasing trend (− 0.77 per 100,000 per year; P = 0.001) since 2001; neither rate was influenced by the intervention.