Estimation of childhood nephrotic syndrome incidence: data from the atlanta metropolitan statistical area and meta-analysis of worldwide cases.

BACKGROUND Epidemiological data on childhood idiopathic nephrotic syndrome (INS) are limited. We estimated childhood INS incidence in a racially and ethnically diverse U.S. population and performed a meta-analysis of published reports to examine differences by race, ethnicity, and time. METHODS One hundred seventy-five children aged 1-17 years living in the Atlanta Metropolitan Statistical Area (MSA) between 2013 and 2018 were identified by retrospective chart review. Annual INS incidence was estimated by dividing cases by population data from the Georgia Department of Public Health. We calculated pooled incidence estimates using random-effects regression models in a meta-analysis of the current and prior studies. Subgroup incidence estimates by race, ethnicity, and time were compared and tested for heterogeneity. RESULTS One hundred seventy-five children aged 1-17 were diagnosed with INS between 2013 and 2018 in the Atlanta MSA. Average annual incidence was 2.13/100,000 (95% CI, 1.83-2.47). Twenty-four studies were included in meta-analysis. Our study was the only one to report incidence for Hispanic children, 2.13/100,000/y (95% CI, 1.40-3.10). In meta-analysis, incidence was highest in Asian children (7.14/ 100,000/y; 95% CI, 4.73-9.54), followed by Black (3.53/100,000/y; 95% CI, 2.93-4.12), and Caucasian (1.83/100,000/y; 95% CI, 1.52-2.14). Annual incidence in the U.S. was stable comparing studies performed before and after 1984, 2.05 vs. 2.26/100,000 (p 0.08). CONCLUSIONS Risk of INS may be higher among Asian and Black children compared to White children. Incidence appears stable over time in the U.S. Future studies should use standardized methodology and assess the contribution of demographic and genetic factors to INS incidence and long-term outcomes.