Association of Diagnostic Criteria with Urinary Tract Infection Prevalence in Bronchiolitis: A Systematic Review and Meta-analysis

Importance: Concomitant urinary tract infection (UTI) is a frequent concern in febrile infants with bronchiolitis, with a prior meta-analysis suggesting a prevalence of 3.3%. However, the definition of UTI in these studies has generally not incorporated urinalysis (UA) results. Objective: To conduct a systematic review and meta-analysis examining the prevalence of UTI in infants with bronchiolitis when positive UA results are incorporated into the UTI definition. Data Sources: Medline (1946-2017) and Ovid EMBASE (1976-2017) through August 2017 and bibliographies of retrieved articles. Study Selection: Studies reporting UTI prevalence in bronchiolitis. Data Extraction: Data were extracted in accordance with meta-analysis of observational studies in epidemiology guidelines via independent abstraction by multiple investigators. Random-effects models generated a weighted pooled event rate with corresponding 95% confidence intervals. Main Outcomes and Measures: Prevalence of UTI. Results: We screened 477 unique articles by abstract, with full-text review of 30 studies. Eighteen bronchiolitis studies reported a UTI prevalence and 7 of these reported UA data for inclusion in the meta-analysis. The overall reported prevalence of UTI in bronchiolitis from these 18 studies was 3.1% (95% CI, 1.8%-4.6%). With the addition of positive UA results (defined as the presence of pyuria or nitrites) as a diagnostic criterion, the prevalence of UTI as reported in the 7 studies in bronchiolitis was 0.8% (95% CI, 0.3%-1.4%). Sensitivity analyses yielded similar results, including for infants younger than 90 days. Heterogeneous definitions of UTI and UA criteria introduced uncertainty into prevalence estimates. Conclusions and Relevance: When a positive UA result is added as a diagnostic criterion, the estimated prevalence of concomitant UTI is less than recommended testing thresholds for bronchiolitis.