Hematuria and subsequent long-term risk of end-stage kidney disease: A Danish population-based cohort study.

BACKGROUND: Hematuria is a frequent incidental clinical finding and may be a symptom of pre-existing underlying benign or malignant urinary tract or kidney disease. However, in patients with no apparent underlying cause of hematuria, long-term prognosis of hematuria remains unknown. OBJECTIVES: To assess the long-term risk of end-stage-kidney disease (ESKD) in patients with a hospital-based hematuria diagnosis and no apparent underlying cause. METHODS: Patients with a hospital diagnosis of hematuria were included and matched in a 1:5 ratio with comparison persons from the background population by age, sex and residency. We calculated the cumulative risk of ESKD considering death as a competing risk. Furthermore, we computed unadjusted and adjusted hazard ratios with 95% confidence intervals using Cox hazard regression with adjustment for age, sex, and comorbidities. RESULTS: We included 170,189 hematuria-diagnosed patients. The absolute 10-year risk of ESKD was 0.7% (95%CI: 0.7-0.8) in patients with hematuria and 0.4% (95%CI: 0.3-0.4) in comparison persons, hence yielding an overall adjusted hazard ratio of 1.6 (95%CI: 1.4-1.7). Hematuria also increased the risk of EKSD in patients with pre-existing comorbidities like diabetes (adjusted HR: 1.3 [95%CI: 1.1-1.5]) and urogenital cancer (adjusted HR: 1.4 ([95%CI: 1.1-1.9]), whereas no association was observed in patients with previous kidney disease (adjusted HR: 0.9 (95%CI: 0.8-1.0). CONCLUSION: A hospital-based hematuria diagnosis in patients with no apparent underlying cause of hematuria is a marker of an increased risk of future ESKD