ASSESSMENT OF THE DIAGNOSTIC ACCURACY OF MICROHEMATURIA VERSUS GROSS HEMATURIA IN THE DIAGNOSIS OF UROLITHIASIS

Background: Urolithiasis, commonly known as kidney stones, is a prevalent condition that affects millions of people worldwide. Hematuria, the presence of blood in the urine, has long been considered an important clinical marker for urolithiasis. Objective: The objective of this study was to assess the diagnostic accuracy of microhematuria and macrohematuria compared to computed tomography (CT) diagnosis as the reference standard for urolithiasis. Additionally, we aimed to evaluate the role of hydronephrosis in diagnosing urolithiasis. Methods: A total of 267 patients with suspected urolithiasis who underwent both CT scans and urine analysis were included in the study. Patients with specific medical conditions that could interfere with the interpretation of the results were excluded. The diagnostic test accuracy of gross hematuria, microscopic hematuria, and hydronephrosis was evaluated by calculating sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with 95% confidence intervals (CIs). Results: The analysis revealed that gross hematuria exhibited a high sensitivity of 98.7% (95% CI: 95.7% - 99.7%) but had a low specificity of 6.0% (95% CI: 2.1% - 14.6%). Microscopic hematuria showed a sensitivity of 97.2% (95% CI: 93.5% - 98.9%) and a specificity of 4.4% (95% CI: 1.5% - 11.2%). Hydronephrosis demonstrated a sensitivity of 100% (95% CI: 97.4% - 100%) but had a specificity of 7.2% (95% CI: 3.2% - 15.3%). The NPV for gross hematuria, microscopic hematuria, and hydronephrosis were 6.0% (95% CI: 2.1% - 14.6%), 4.4% (95% CI: 1.5% - 11.2%), and 0% (95% CI: 0% - 2.7%), respectively. Conclusion: Gross hematuria and microscopic hematuria showed high sensitivity but low specificity in diagnosing urolithiasis. Hydronephrosis exhibited excellent sensitivity but limited specificity and a low NPV. These findings highlight the importance of a comprehensive diagnostic approach that combines clinical evaluation, urine analysis, and imaging modalities such as CT scans to achieve accurate urolithiasis diagnosis. Clinicians should interpret hematuria findings cautiously due to the potential for false-positive results. Integrating these parameters into a diagnostic algorithm can assist in clinical decision-making and patient management. Further research is needed to validate these findings in larger and more diverse populations.