title: Cost-effectiveness of a new system in ruling out negative urine cultures on the day of administration.
abstract: Urine samples account for a significant part of the workload in clinical microbiology laboratories. However, the culture process is time-consuming and a large proportion is reported as negative. To reduce unnecessary culture procedures and speed up the reporting of negative results, a reliable screening method is needed. For this purpose, urine samples submitted to our clinical microbiology laboratory were simultaneously screened by a flow cytometry method (Sysmex UF-1000i, Japan). During screening, the evaluation of various combinations of leucocytes and bacteria cut-offs demonstrated that cut-offs of 30 and 50/μL, respectively, were the best threshold values to reach a 100% negative predictive value (NPV) with a culture reduction rate of 44.8% in adults and 61.9% in children between the ages of 6 and 17 years. With the culture reduction rates mentioned above, the screening method has provided at least 24% savings in expenditures of the routine clinical microbiology laboratory. Since we did not reach such an NPV with any combinations of screening parameters in children younger than 5 years of age, we recommend cultivation of all urine samples in those patients without a screening step. In conclusion, Sysmex UF-1000i as a screening method was capable of improving the efficiency of the routine microbiology laboratory by providing negative results in a few minutes in children greater than 6 years of age and in adults.
authors.affiliation: Marmara University School of Medicine, Istanbul, Turkey. ailki@marmara.edu.tr.
authors.forename: A
authors.initials: A
authors.lastname: Ilki
authors.affiliation: Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: R
authors.initials: R
authors.lastname: Ayas
authors.affiliation: Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: S
authors.initials: S
authors.lastname: Ozsoy
authors.affiliation: Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: G
authors.initials: G
authors.lastname: Soyletir
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001431:Bacteriological Techniques / Q000191:economics / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D003362:Cost-Benefit Analysis; D003955:Diagnostic Tests, Routine / Q000191:economics / Q000379:methods*; D005260:Female; D005434:Flow Cytometry / Q000191:economics / Q000379:methods*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D008297:Male; D008403:Mass Screening / Q000191:economics / Q000379:methods*; D008875:Middle Aged; D014552:Urinary Tract Infections / Q000175:diagnosis*; D014556:Urine / Q000382:microbiology*; D055815:Young Adult