During the same period, there were 43, 580 cases of acute pancreatitis in the overall population, including 226 cases (0.5%) among methimazole users and 19 cases (0.04%) among PTU users, with a case-crossover analysis showing an odds ratio (OR) of 1.51 (95% CI, 1.12 - 2.02) for acute pancreatitis among methimazole users and an OR of 1.16 (95% CI, 0.46 - 2.93) among PTU users, respectively.