History and physical examination plus laboratory testing for the diagnosis of adult female urinary tract infection.Acad Emerg Med. 2013 Jul; 20(7):631-45.AE
Emergency physicians often encounter females presenting with symptoms suggestive of urinary tract infections (UTIs). The diagnostic accuracy of history, physical examination, and bedside laboratory tests for female UTIs in emergency departments (EDs) have not been quantitatively described.
This was a systematic review to determine the utility of history and physical examination (H&P) and urinalysis in diagnosing uncomplicated female UTI in the ED.
The medical literature was searched from January 1965 through October 2012 in PUBMED and EMBASE using the following criteria: Patients were females greater than 18 years of age in the ED suspected of having UTIs. Interventions were H&P and urinalysis used to diagnose a UTI. The comparator was UTI confirmed by a positive urine culture. The outcome was operating characteristics of the interventions in diagnosing a UTI. Study quality was assessed using Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2). Sensitivity, specificity, and likelihood ratios (LRs) were calculated using Meta-DiSc.
Four studies (pooled n = 948) were included with UTI prevalence ranging from 40% to 60%. H&P variables all had positive LRs (+LR, range = 0.8 to 2.2) and negative LRs (-LR, range = 0.7 to 1.0) that are insufficient to significantly alter pretest probability of UTI. Only a positive nitrite reaction (+LR = 7.5 to 24.5) was useful to rule in a UTI. To rule out UTI, only a negative leukocyte esterase (LE; -LR = 0.2) or blood reaction on urine dipstick (-LR = 0.2) were significantly accurate. Increasing pyuria directly correlated with +LR, and moderate pyuria (urine white blood cells [uWBC] > 50 colony-forming units [CFUs]/ml) and moderate bacteruria were good predictors of UTI (+LR = 6.4 and 15.0, respectively).
No single H&P finding can accurately rule in or rule out UTI in symptomatic women. Urinalysis with a positive nitrite or moderate pyuria and/or bacteruria are accurate predictors of a UTI. If the pretest probability of UTI is sufficiently low, a negative urinalysis can accurately rule out the diagnosis.