#2680 Differences in chronic kidney disease management based on identification and diagnosis in a population-based observational study

Abstract Background and Aims Chronic kidney disease (CKD), affecting 6–10% of adults, often progresses silently until advanced stages, resulting in frequent underdiagnosis and inadequate management. To compare diagnosed, proxy-diagnosed, and undiagnosed CKD patients in terms of prevalence, assessment, nephroprotective treatment, healthcare utilization, and mortality. Method A retrospective observational study using Region Halland's healthcare data included adults meeting the confirmed CKD criteria defined by Kidney Disease: Improving Global Outcomes (KDIGO) from January–December 2019. Participants were classified into three groups: ICD-coded CKD (diagnosed CKD), CKD-related diagnoses (proxy-diagnosed CKD), and those meeting CKD criteria without an ICD diagnosis (undiagnosed CKD). Results Among 20488 CKD patients, 21% had an ICD-documented diagnosed CKD, 18% had a proxy-diagnosed CKD, and 61% were undiagnosed CKD. The mean ages were 76.4 years for diagnosed CKD, 62.4 years for proxy-diagnosed CKD, and 81.8 years for undiagnosed CKD (P < 0.001). Blood pressure follow-up rates were 88% for diagnosed, 67% for proxy-diagnosed, and 80% for undiagnosed, while glucose testing rates were 83%, 69%, and 76%, respectively. eGFR testing rates were 73%, 53%, and 66%. Urine albumin-creatinine ratio (UACR) testing rates were 25% in the overall population, 45% among individuals with diagnosed CKD, and 19% in both the undiagnosed CKD and proxy-diagnosed CKD groups. Renin-angiotensin system inhibitors were used in 45% of the cohort: 51% in diagnosed CKD, 28% in proxy-diagnosed CKD, and 47% in undiagnosed CKD. The relative risk of hospitalization, adjusted for age and comorbidities, was 2.71 (CI: 2.59–2.84) for patients with diagnosed CKD and 1.38 (CI: 1.31–1.46) for those with proxy-diagnosed CKD. The adjusted all-cause mortality hazard ratios were 2.22 (CI: 1.95–2.52) for CKD-diagnosed patients and 1.31 (CI: 1.08–1.60) for those with a proxy-diagnosed CKD. Conclusion The study highlights gaps in CKD diagnosis and management, with many patients remaining undiagnosed despite meeting CKD criteria. Diagnosed CKD patients received better follow-up but faced higher risks of hospitalization and mortality due to more complex comorbidities and more advanced CKD. Proxy-diagnosed CKD were common and associated with suboptimal management. These findings emphasize the need for consistent and accurate CKD identification to improve outcomes and optimize care.