Accuracy of Onsite Tests to Detect Asymptomatic Bacteriuria in Pregnancy: A Systematic Review and Meta-analysis

OBJECTIVE: To estimate the accuracy of onsite tests to detect asymptomatic bacteriuria among pregnant women. DATA SOURCES: We searched MEDLINE, EMBASE, Web of Science, Scopus, and Latin-American Literature from inception until June 2015 without language restrictions. The ClinicalTrials.gov register database was screened to identify any recently completed studies. METHODS OF STUDY SELECTION: Two independent reviewers selected studies that recruited asymptomatic pregnant women to evaluate the accuracy of onsite tests in detecting the presence of bacteria in the urine using urine culture as a reference standard. TABULATION, INTEGRATION, AND RESULTS: Women's characteristics, study design, urine sample collection, and handling were extracted along with the test accuracy data. Where possible, we pooled the data using a bivariate, hierarchical random-effects model. Of 1,360 screened references, 27 articles (13,641 women) with test accuracy data on nine tests met the inclusion criteria. The most commonly evaluated test was urine dipstick. The pooled sensitivity and specificity of nitrites detected by dipstick to detect asymptomatic bacteriuria were 0.55 (95% confidence interval [CI] 0.42-0.67) and 0.99 (95% CI 0.98-0.99), respectively. The Griess test to detect nitrites had a sensitivity of 0.65 (95% CI 0.50-0.78) and specificity of 0.99 (95% CI 0.98-1.00). Dipslide with Gram staining had a pooled sensitivity of 0.86 (95% CI 0.80-0.91) and specificity of 0.97 (95% CI 0.93-0.99). CONCLUSION: The specificity of onsite tests is high; however, the sensitivity is not with the result that they will fail to detect a substantial number of cases of asymptomatic bacteriuria. CLINICAL TRIAL REGISTRATION: PROSPERO International prospective register of systematic reviews, http://www.crd.york.ac.uk/PROSPERO/, CRD42015027905.