The perineal adhesive bag is the most commonly used method in our country for
urine culture collection in infants, despite having a high risk of
contamination and false-positive results. We aim to quantify both types of risks through a systematic review.
Methods
Search updated in May 2014 in PUBMED, SCOPUS (includes EMBASE), IBECS; CINAHL, LILACS AND CUIDEN, unrestricted by language or date. Percentage of contaminated samples, false positives, sensitivity and specificity (with respect to catheterization or bladder puncture) were recorded.
Results
A total of 21 studies of medium quality (7659 samples) were selected. The pooled percentage of contaminated samples was 46.6% (15 studies; 6856 samples; 95% confidence interval [95% CI]: 35.6–57.8%; I2: 97.3%). The pooled percentage of false positives was 61.1% (12 studies; 575 samples; 95% CI: 37.9–82.2%; I2: 96.2%). Sensitivity (88%; 95% CI: 81–93%; I2: 55.2%) and specificity (82%; 95% CI: 75–89%; I2: 41.3%) were estimated in five studies, but without including contaminated samples.
Conclusion
The perineal adhesive bag is not a valid enough method for urine culture collection, because almost half of all samples are contaminated, and two out of three positives are false. Although these estimates are imprecise, because of their great heterogeneity, they should be considered when choosing the method of urine collection. The estimates of sensitivity and specificity are not applicable because they do not take into account the risk of contamination.
