Efficient use of laboratory resources: pre-screening for urine cultures by automated urinalysis and microscopy to allow exclusion of specimens from culture workflow

Abstract

Abstract Background: Most of the urine cultures give negative results, leading to inefficient use of resources. The aim of this study was to evaluate and optimize screening by urinalysis and urine microscopy allowing elimination from the culture workflow, and find out if it might be cost effective in Turkey. Methods: A total of 1511 urine specimens were evaluated. Urinalysis and automated microscopy was performed by Iris iQ200 (Iris Diagnostics, USA). Results for nitrite, leukocyte esterase (LE), white blood cell (WBC), red blood cell (RBC) and all small particles (ASP) were compared to urine culture results. Savings were calculated, in case specimens predicted to be negative were not cultured. Results: Microbial growth was detected in 279 (18.5%) specimens. Using the most efficient algorithm, 400 (26.5%) specimens could be excluded from the workflow, leading to three (0.2%) false negatives. Second algorithm could predict negative result for 15.7% of the specimens with a negative predictive value (NPV) of 100%, saving $562. Conclusions: Screening urine specimens using multiple criteria might help predicting urine culture results. Although the cost of urine culture is low in Turkey, screening might still decrease cost and workload. All the variables should be considered to achieve efficient management of resources in the healthcare system without compromising patient safety.