an increasing trendp < 0.001
Secular trend of KD incidence The KD incidence of subjects younger than 18 years significantly increased from 11.78 per 100,000 person-years in 2001 to 22.40 per 100,000 person-years in 2020 (AAPC = 5.4%, p < 0.001, Table 1 ), and 97.1% of KD patients were aged 0–5 years, which also demonstrated an increasing trend with an AAPC of 4.2% ( p < 0.001, Table 1 ; Fig. 1 a).