title: Cut-off values to rule out urinary tract infection should be gender-specific.
abstract: The diagnosis of urinary tract infection (UTI) by urine culture is an expensive and time-consuming procedure. Using a screening method, to identify negative samples, would improve the procedure and reduce costs. In this study, urine flow cytometry, of over 7000 urine samples, was assessed by retrospective analysis. With a cut-off value of >200bacteria/μl, we obtained a sensitivity of 93.0%, a specificity of 63.5%, and a negative predictive value (NPV) of 96.2%. As a result the culturing of 49% of all samples could be avoided. In addition, the data was retrospectively analyzed to determine if the introduction of gender-specific cut-off values could improve screening results. The obtained receiver operator curves are indeed significantly different when gender specific cut-offs were used. When a NPV of 95% is considered acceptable the unisex cut-off value of >200bacteria/μl can be used for women (NPV 94.9%), but the cut-off value for men could be raised to >400bacteria/μl without diminishing the NPV (NPV 95.0%).
authors.affiliation: Clinical Laboratory, Catharina Hospital Eindhoven, Michelangelolaan 2, 5623 EJ Eindhoven, The Netherlands. Electronic address: nienke.geerts@catharinaziekenhuis.nl.
authors.forename: N
authors.initials: N
authors.lastname: Geerts
authors.affiliation: Clinical Laboratory, Catharina Hospital Eindhoven, Michelangelolaan 2, 5623 EJ Eindhoven, The Netherlands. Electronic address: kboonen@amphia.nl.
authors.forename: K J M
authors.initials: KJ
authors.lastname: Boonen
authors.affiliation: Clinical Laboratory, Catharina Hospital Eindhoven, Michelangelolaan 2, 5623 EJ Eindhoven, The Netherlands. Electronic address: arjen-kars.boer@catharinaziekenhuis.nl.
authors.forename: A K
authors.initials: AK
authors.lastname: Boer
authors.affiliation: Clinical Laboratory, Catharina Hospital Eindhoven, Michelangelolaan 2, 5623 EJ Eindhoven, The Netherlands. Electronic address: volkher.scharnhorst@catharinaziekenhuis.nl.
authors.forename: V
authors.initials: V
authors.lastname: Scharnhorst
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012016:Reference Values; D012189:Retrospective Studies; D012727:Sex Characteristics; D014552:Urinary Tract Infections / Q000175:diagnosis* / Q000652:urine*
keywords: Gender-specific; Screening; UF500; UTI