Fig. 1: Incidence of type 1 diabetes according to birth year.

HR hazard ratio, CI confidence interval. A HR (95% CI) of type 1 diabetes in each birth year (n = 2,928,704). The solid circles represent the point estimates of HRs, calculated as exponential of regression coefficients in Cox models, while error bars represent 95% CIs, calculated as exponential of (β coefficients±1.96×standard errors). Cox models were fitted with the birth year of 1982 as the reference group, with attained age as the time scale and with adjustment for sex. Cluster robust sandwich estimator for standard errors were used to correct for the dependence among individuals born by the same mother. Source data (the exact values for HRs and 95% CIs) are provided as a Source Data file. B Cumulative incidence of type 1 diabetes before age 19 years in people born in different birth years was estimated using Kaplan Meier curves. The red, green, blue, and orange shaded areas represent the 95% CIs, calculated as cumulative incidence estimates ±1.96×standard errors, for birth year 1982, 1990, 2000, and 2010, respectively.