Secular trend of the T1D incidence (per 100,000 person-years) in Taiwan by different age groups during 2001–2015. Subjects aged 0–6 years (A), 7–12 years (B), 13–19 years (C), and 0–19 years (D). The P values for trend were obtained from negative binomial regression models for subjects aged 0–6 years, 7–12 years, and 0–19 years. The P value for trend was obtained from the autoregressive error model with AR(1) for subjects aged 13–19 years. The I bars show the 95% CIs.