Validation of a Quantitative Hematuria Scale

To develop a quantitative hematuria scale that assigns specific blood concentration percentages to commonly used descriptors such as "clear," "mild," "moderate," and "severe" in order to standardize hematuria severity assessments during continuous bladder irrigation and reduce reliance on subjective visual evaluations.

Samples of bovine blood with concentrations ranging from 0% to 100% were created, photographed, and distributed to a cohort of urologists and healthcare workers in a survey. Respondents were asked to categorize these samples as clear, mild, moderate, or severe. Fleiss' kappa analysis was performed to evaluate the inter-rater agreement.

Data from 39 respondents were analyzed, and consensus categories for each blood concentration were determined using mode and weighted averages. Overall agreement among respondents was moderate (Kappa = 0.53, P <.0001). The categories "clear" and "severe" demonstrated substantial agreement (Kappa = 0.63), while "moderate" and "mild" showed moderate and fair agreement, respectively.

This study presents a promising foundation to a novel quantitative scale for hematuria assessment, reducing reliance on subjective visual judgments. The scale would enable clearer and more consistent communication of hematuria severity, which is crucial as urological technologies advance toward quantitative measurements.