Screening tests for urinary tract infection in children: A meta-analysis

Objective. To review systematically and to summarize the existing literatur e regarding performance of rapid diagnostic tests for urinary tract infecti on (UTI) in children. Design. Systematic review and meta-analysis. Methods. Published articles reporting the performance of urine dipstick tes ts (leukocyte esterase [LE] and/or nitrite), Gram stain, or microscopic ana lysis of spun or unspun urine in the diagnosis of UTI in children less than or equal to 12 years of age. Articles were identified through a comprehens ive MEDLINE search, and those articles meeting a priori inclusion criteria were selected. Eligibility criteria included the use of urine culture as th e reference standard, independent comparison of urine culture with the resu lts of one of the screening tests, definition of positive screening test re sults provided, only pediatric patients included or evaluable separately, a nd both gold standard and screening test performed on all patients. For eac h test, heterogeneity of reported sensitivity and specificity of all studie s was determined. The subgroups of studies with similar definitions of UTI and age of study subjects were analyzed separately to account for some of t he differences in reported results. When significant unexplained heterogene ity among studies precluded simple combining of results, a summary receiver -operator characteristic curve was fitted for each screening test, from whi ch pooled estimates of true-positive rate (TPR; ie, sensitivity) and false- positive rate (FPR; 1-specificity) were calculated. Primary Results. A total of 1489 titles were identified by the MEDLINE sear ch; 26 articles met all criteria for inclusion. There was significant heter ogeneity among studies for nearly all tests for both TPR and FPR, which was explained only partially by the stringency of the definition of UTI or age of subjects studied. Based on the pooled estimates, the presence of any ba cteria on Gram stain on an uncentrifuged urine specimen had the best combin ation of sensitivity (0.93) and FPR (0.05). Urine dipstick tests performed nearly as well, with a sensitivity of 0.88 for the the presence of either L E or nitrite and an FPR of 0.04 for the presence of both LE and nitrite. Py uria had lower TPR and higher FPR: for presence of >5 white blood cells/hig h-power field in a centrifuged urine sample, the TPR was 0.67 and the FPR w as 0.21, whereas for >10 white blood cells per mm(3) in uncentrifuged urine , the TPR was 0.77 and the FPR was 0.11. Conclusions. Both Gram stain and dipstick analysis for nitrite and LE perfo rm similarly in detecting UTI in children and are superior to microscopic a nalysis for pyuria.