Background The effectiveness of identifying and monitoring early-stage chronic kidney disease (CKD) is not fully recognised. This study quantified people with undiagnosed CKD among the middle-aged Japanese population and clarified potential risks of untreated CKD.
Methods We included 71 233 individuals who underwent annual health check-ups (AHC) in 2014 for both baseline and follow-up proteinuria and serum creatine measurements. CKD was identified by AHC data as proteinuria or estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. We differentiated undiagnosed from diagnosed CKD using the medical claims database. In undiagnosed CKD, we assessed risk differences for disease progression, defined as an eGFR decline slope >3 mL/min/1.73 m2/year or proteinuria incidence over 3 years, between those who visited a physician for CKD treatment within 6 months after AHC and those who did not.
Results CKD prevalence was 5.7% (5.2% undiagnosed and 0.5% diagnosed). Only 2.1% of the patients with undiagnosed CKD visited a physician for CKD treatment within 6 months after AHC. Between-group risk differences in instrumental variable adjustment models showed that those left untreated progressed to kidney diseases 16.3% more often than those who visited physicians for CKD treatment.
Conclusion CKD was undiagnosed in 5.2% of the middle-aged general population. Only a few people visited physicians for CKD treatment. Visiting physicians for CKD treatment during the first 6 months after screening may be associated with a lower risk of kidney disease progression.
- population prevalence
- early identified CKD
- annual screening
- instrumental variable analysis
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Contributors SF conceived the concept and design of the work. SF, TI and YS contributed the acquisition of data. YY did the analysis, interpretation of data for the work, and drafted the manuscript. All authors revised it critically for important intellectual content and gave final approval of the version to be published.
Funding This work is supported by the Japan Society for the Promotion of Science KAKENHI (grant number: 16K19251).
Disclaimer The funding sources had no involvement in conducting the study.
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval The Institutional Review Board (IRB) of Kyoto University approved the study (R0817). We analysed the data anonymously, and the IRB waived informed and signed consent for this observational study from each participant. This research was conducted in accordance with the principles embodied in the Declaration of Helsinki.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available upon reasonable request.
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