Before the pandemic, there was a slight insignificant increasing trend in opioid poisonings that changed significantly after the pandemic (1.47 cases per month, p-value = 0.006, Table 3 ) and led to an increasing trend of 1.53 monthly cases during the pandemic (p-value < 0.001).
The trend slope changed in a decreasing manner (− 0.798, 95% CI − 1.233 to − 0.363, p-value = 0.001), resulting in a decreasing trend of − 0.622 cases (p-value = 0.003).
Also, the change in slope was increasing despite being insignificant which resulted in a significant trend of 0.335 cases/month during the COVID-19 period (p-value = 0.029) (Fig. 2 G).