Dipstick Urinalysis as a Test for Microhematuria and Occult Bladder Cancer

Introduction: There is a lack of evidence supporting the routine use of laboratory tests to detect bladder cancer.Identifying a cost-effective and widely available diagnostic aid may improve bladder cancer outcomes.We sought to evaluate the utility of dipstick urinalysis to detect microhematuria and diagnose bladder cancer in a large, diverse, contemporary cohort.Methods: All non-pregnant women and men 35 and older with a new diagnosis of microhematuria (≥3 RBC/hpf) were identified via a multi-center electronic medical record data warehouse query.Negative controls with no history of hematuria were randomly chosen and included to complete our cohort.Comparison between dipstick urinalysis and microscopic urinalysis on self-matched patients for the detection of microhematuria and diagnosis of bladder cancer was performed via Spearman's rank correlation coefficient, sensitivity/specificity testing, and ROC curve analysis.Results: A total of 46,842 patients were included.Spearman's rank order correlation (rho = 0.66) between degree of microhematuria on dipstick urinalysis and microscopic urinalysis indicated a strong positive relationship.The ROC curve for dipstick urinalysis to identify microhematuria had an AUC of 0.80 (95% CI 0.79-0.81).No difference (p = 0.83) in diagnostic accuracy between dipstick urinalysis (AUC 0.74, 95% CI 0.70-0.78)and microscopic urinalysis (AUC 0.73, 95% CI 0.69-0.78)as a test for bladder cancer was found.Conclusion: Dipstick urinalysis provides a highly specific test for microhematuria and similar accuracy to microscopic urinalysis when used as a diagnostic tool to detect bladder cancer.