Evaluating the pyuria threshold for diagnosing urinary tract infection in postmenopausal women: a case-control study

Urinary tract infections (UTIs) in postmenopausal women ≥65 years are common with pyuria rates which can also happen from atrophic vaginitis. The conventional pus cells cutoff lacks geriatric validation especially elderly females.

This study was a prospective case-control study enrolled 300 postmenopausal women with suspected UTI. Urine microscopy evaluated pyuria at 10, 17, and 20/HPF cutoffs against culture gold standard, selecting 150 culture-positive and 150 culture-negative cases. Along with urine leukocyte esterase detection test performance was compared. These methods were statistically analysed for sensitivity, specificity, predictive values, and Youden index to evaluate new pyuria cut off for elderly females with UTI.

The conventional microscopy cut off 17/HPF demonstrated optimal performance: sensitivity 61.3% (95% CI: 53.2-69.0%), specificity 48.7% (95% CI: 40.6-56.8%), Youden index 0.100 (highest). Whereas the standard pyuria of 10/HPF showed high sensitivity (72.7%) but poor specificity (14.0%, 86% FPR). Simultaneously a cut off 20/HPF achieved 58.7% specificity but missed 63% cases.

An integrated approach combining urine microscopy with culture confirmation may improve diagnostic decision-making and warrants validation in prospective cohort studies.