Association of maternal ethnicity and urbanicity on severe pediatric disease: a nationwide cohort study

BACKGROUND: A healthy migrant effect on birth outcomes has been reported, however, whether this protective effect persists throughout childhood is unknown. The effect of urbanicity on child health among an immigrant population is unclear. The objective of this study was to compare the incidence rate and cumulative incidence of severe diseases among urban children of Taiwan-born mothers, rural children of Taiwan-born mothers, urban children of foreign-born mothers, and rural children of foreign-born mothers. METHODS: A nationwide cohort study was conducted for children born in Taiwan during 2004–2011 and follow-up till age 4 to 11 years old by linkage the Taiwan Birth Registry 2004–2011, Taiwan Death Registry 2004–2015, and National Health Insurance Research Database 2004–2015. Cox proportional hazards model (multivariable) was used to examine differences among the four study groups. RESULTS: There were 682,982 urban children of Taiwan-born mothers, 662,818 rural children of Taiwan-born mothers, 61,570 urban children of foreign-born mothers, 87,473 rural children of foreign-born mothers. Children of foreign-born mothers had a lower incidence of vasculitis, mainly Kawasaki disease. The incidences of congenital disorders did not differ between children of foreign-born mothers and children of Taiwan-born mothers. The incidence of psychotic disorders was higher in urban children. However, children in rural areas had a higher incidence of major trauma/burn and a higher mortality rate. CONCLUSIONS: A healthy migrant effect was only seen for Kawasaki disease. The mental health of urban children born to immigrant mothers warrants concern.