Does clinical examination aid in the diagnosis of urinary tract infections in women? A systematic review and meta-analysis

Abstract

Background: Clinicians should be aware of the diagnostic values of various symptoms, signs and antecedents. This information is particularly important in primary care settings, where sophisticated diagnostic approaches are not always feasible. The aim of the study is to determine the probability that various symptoms, signs, antecedents and tests predict urinary tract infection (UTI) in women.

Methods: We conducted a systematic search of the MEDLINE and EMBASE databases to identify articles published in all languages through until December 2008. We particularly focused on studies that examined the diagnostic accuracy of at least one symptom, sign or patient antecedent related to the urinary tract. We included studies where urine culture, a gold standard, was preformed by primary care providers on female subjects aged at least 14 years. A meta-analysis of the likelihood ratio was performed to assess variables related to the urinary tract symptoms.

Results: Of the 1, 212 articles identified, 11 met the selection criteria. Dysuria, urgency, nocturia, sexual activity and urgency with dysuria were weak predictors of urinary tract infection, whereas increases in vaginal discharge and suprapubic pain were weak predictors of the absence of infection. Nitrites or leukocytes in the dipstick test are the only findings that clearly favored a diagnosis of UTI.

Conclusions: Clinical findings do not aid in the diagnosis of UTI among women who present with urinary symptoms. Vaginal discharge is a weak indicator of the absence of infection. The urine dipstick test was the most reliable tool for detecting UTI.

Figure 1

Summary of exclusion of studies.

Figure 2

Comparative estimate of the number of times a woman with a urinary tract infection (UTI) is more likely than a woman without a UTI to present with certain clinical findings (i.e., pooled positive likelihood ratios - PLRp - and confidence intervals for all clinical findings).

Figure 3

Comparative estimate of the number of times a woman with a urinary tract infection (UTI) is more likely than a woman without a UTI to lack certain clinical findings (i.e., pooled negative likelihood ratios - NLRp - and confidence intervals for all clinical findings).

Figure 4

Comparative usefulness of clinical findings in the diagnosis of urinary tract infections. The pooled diagnostic odds ratio (DORp) values estimate the accuracy of the test (i.e., clinical finding) in patients with and without disease, as well as the discriminatory properties of positive and negative test results (PLR and NLR, respectively).