“…The present study suggested that the quantification of leukocytes in FVU with automated quantitative urine particle analyzers might have good performance for predicting the presence or absence of chlamydial infection. When the threshold value of 12.5 WBCs/ml determined in this study is used and the pre-test probability of C. trachomatis is assumed to range from 5% to 10% in asymptomatic adolescent men [18], the positive and negative predictive values of the quantification of leukocytes in FVU can be calculated to be 28.7% (95% CI, 5.9e51.5%) to 45.9% (95% CI, 23.4e68.3%) and 99.2% (95% CI, 97.2e100%) to 98.4% (95% CI, 95.6e100%), respectively. The post-test probability of the positivity for C. trachomatis in an asymptomatic man in these populations with low prevalence of C. trachomatis infections, who has a negative test result for quantification of leukocytes in FVU with an automated particle analyzer, can be calculated to be 0.8e1.6%.…”