How many urinalysis and urine cultures are necessary?

Bart J Laan,Tessa M.Z.X.K Van Horrik,Prabath W.B Nanayakkara,Suzanne E Geerlings

doi:10.1016/j.ejim.2020.08.013

Abstract

BackgroundUrinalysis and urine culture are two of the most commonly ordered tests. A positive urine test in asymptomatic patients often leads to overtreatment. Antimicrobials for asymptomatic bacteriuria is one of the most common unnecessary treatments. We aimed to explore the current ordering patterns of urinalysis and cultures. MethodsThis is a substudy of the multicentre RICAT-trial, a successful quality improvement project to reduce inappropriate use of intravenous and urinary catheters in seven hospitals in the Netherlands. Adult patients with a (central or peripheral) venous or urinary catheter admitted to internal medicine and non-surgical subspecialty wards were eligible for inclusion. Data were collected every other week during baseline (seven months) and intervention periods (seven months). The primary outcome was the proportion of urine cultures performed following a negative urinalysis, i.e. dipstick and/or microscopic analysis, within 24 h. ResultsBetween September 2016 and April 2018, we included 3748 patients, of which 3111 (83%) were admitted from the emergency department. Urinalysis and/or urine cultures were obtained in 2610 (70%) of 3748 patients. 626 (23.7%) of 2636 urine cultures and 1351 (55.8%) of 2419 microscopic analysis were unnecessary performed after a negative urinalysis. Cancelling urine testing orders after a negative dipstick would have saved almost € 19.500 during the study period in these seven hospitals. ConclusionUnnecessary urine testing is frequent in non-surgical patients in the Netherlands. We need to take action to reduce unnecessary urinalysis and cultures, and thereby probably reduce overtreatment of asymptomatic bacteriuria.

Highlights

Low-value care is defined as a test or treatment that is unlikely to benefit the patient given the cost, available alternatives, and preferences of patients, [1] and can even cause harm to patients [2]
The results of a recent retrospective cohort study in 46 hospitals in the United States showed that 83% (2259/2733) patients with asymptomatic bacteriuria were treated with antibiotics [5]
Reflex urine culture cancellation, which means that cultures are automatically cancelled if urinalysis is negative

Summary

Introduction

Low-value care is defined as a test or treatment that is unlikely to benefit the patient given the cost, available alternatives, and preferences of patients, [1] and can even cause harm to patients [2]. The sensitivity of urinalysis and cultures for urinary tract infections is low in asymptomatic patients, and should not be ordered in these patients. Positive urinalysis and urine cultures with a bacterial colony count more than 100,000 CFU per high-power field were the main risk factors for overtreatment of asymptomatic bacteriuria in this study [5]. This is reported in a qualitative study that determined the reasons for using antibiotics to treat ASB in the internal medicine in Switzerland [6]. Cancelling urine testing orders after a negative dipstick would have saved almost € 19.500 during the study period in these seven hospitals. We need to take action to reduce unnecessary urinalysis and cultures, and thereby probably reduce overtreatment of asymptomatic bacteriuria

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Conclusion