Trends in 10th Revision of the International Classification of Diseases–Coded CKD Incidence Among Chinese Adults

Introduction: Chronic kidney disease (CKD) is a growing public health concern, yet evidence on its incidence is limited in China. Methods: Using data from the China Kadoorie Biobank (CKB), which recruited 512,723 participants aged 30 to 79 years from 10 areas across China, we analyzed 5 major CKD subtypes: diabetic kidney disease (DKD), hypertensive nephropathy (HTN), glomerulonephritis (GN), chronic tubulointerstitial nephritis (CTIN), and obstructive nephropathy (ON). Total CKD included the aforementioned subtypes, CKD due to other reasons, or chronic kidney failure. Outcomes were ascertained through linkages to local death and disease registries and health insurance databases until December 31, 2018. Poisson regression model was used to assess secular trends and population variations. Results: Over a mean of 9.5 years of follow-up, 5662 total CKD cases were identified. The crude incidence rate (per 100,000 person-years) of total CKD was 119.7 (95% confidence interval: 116.6-122.8) between 2009 and 2018, with an annual increase of 8.9% (7.9%-10.0%) after adjusting for age, sex, and study area. The crude incidence rates were highest in GN, whereas biggest increases were observed in ON, DKD, and HTN. Total CKD incidence rate was similar between urban and rural areas; however, those of different subtypes varied: DKD or CTIN were higher in urban areas, and ON was significantly higher in rural areas. Males, older adults, and participants with hypertension or diabetes mellitus were at higher risks. Conclusion: Despite the underestimation of CKD incidence because of outcome ascertainment methods, the incidence of total CKD and its subtypes increased in the CKB population during 2009 to 2018. Measures should be taken against major driving factors, such as diabetes mellitus, hypertension, and kidney stones.