By comparison with the period of June 1997 to May 1998, significantly lower incidence were observed in people with type 1 diabetes (IRR = 0.720, 95% CI: 0.580–0.892, p < 0.001) and people with type 2 diabetes receiving insulin (IRR = 0.314, 95% CI: 0.249–0.395, p = 0.008). Here, INS is linked to type 2 diabetes mellitus.