Neutrophil-to-lymphocyte ratio for the diagnosis of pediatric acute appendicitis: a systematic review and meta-analysis.

OBJECTIVE: Acute appendicitis (AA) is one of the most common surgical emergencies and causes of acute abdominal pain in the pediatric population. However, it can be difficult to diagnose in children. We aimed to provide updated evidence on the diagnostic utility of the neutrophil-to-lymphocyte ratio (NLR) for AA, along with other conventional biomarkers, in pediatric patients. MATERIALS AND METHODS: We searched the PubMed, Embase, Cochrane Library, and Web of Science databases for eligible articles published up to May 16, 2021. RESULTS: We included 19 studies comprising a total of 5,974 pediatric cases. The overall sensitivity and specificity of the NLR were 0.82 (95% confidence interval [CI]: 0.79-0.85) and 0.76 (95% CI: 0.69-0.81), respectively. The overall diagnostic odds ratio was 14.34 (95% CI: 9.05-22.73). The area under the summary receiver operating characteristic curve was 0.86 (95% CI: 0.83-0.89). The pooled sensitivity and specificity of other biomarkers were as follows: 0.79 (95% CI: 0.71-0.86) and 0.66 (95% CI: 0.54-0.77) for the white blood cell count, 0.73 (95% CI: 0.69-0.77) and 0.68 (95% CI: 0.55-0.79) for the C-reactive protein level, 0.75 (95% CI: 0.65-0.82) and 0.78 (95% CI: 0.72-0.83) for the absolute neutrophil count, and 0.83 (95% CI: 0.79-0.87) and 0.68 (95% CI: 0.53-0.80) for the neutrophil percentage, respectively. CONCLUSIONS: The NLR has moderate predictive power for AA and can be used as a simple, auxiliary tool for diagnosis. NLR can also help clinicians decide whether to perform imaging testing when the clinical symptoms or physical examination findings are vague.