Evaluation of the New American Urological Association Guidelines Risk Classification for Hematuria

Purpose:Microhematuria is a prevalent condition and the American Urological Association has developed a new risk-stratified approach for the evaluation of patients with microhematuria. Our objective was to provide the first evaluation of this important guideline.Materials and Methods:This multinational cohort study combines contemporary patients from 5 clinical trials and 2 prospective registries who underwent urological evaluation for hematuria. Patients were stratified into American Urological Association risk strata (low, intermediate or high risk) based on sex, age, degree of hematuria, and smoking history. The primary end point was the incidence of bladder cancer within each risk stratum.Results:A total of 15,779 patients were included in the analysis. Overall, 727 patients (4.6%) were classified as low risk, 1,863 patients (11.8%) were classified as intermediate risk, and 13,189 patients (83.6%) were classified as high risk. The predominance of high risk patients was consistent across all cohorts. A total of 857 bladder cancers were diagnosed with a bladder cancer incidence of 5.4%. Bladder cancer was more prevalent in men, smokers, older patients and patients with gross hematuria. The cancer incidence for low, intermediate and high risk groups was 0.4% (3 patients), 1.0% (18 patients) and 6.3% (836 patients), respectively.Conclusions:The new risk stratification system separates hematuria patients into clinically meaningful categories with differing likelihoods of bladder cancer that would justify evaluating the low, intermediate and high risk groups with incremental intensity. Furthermore, it provides the relative incidence of bladder cancer in each risk group which should facilitate patient counseling regarding the risks and benefits of evaluation for bladder cancer.