Contemporary Epidemiology of and Risk Factors Associated with Removal of a Pathologically Normal Appendix in Children with Suspected Appendicitis.

BACKGROUND: The goal of this study was to characterize contemporary performance benchmarks and risk factors associated with negative appendectomy (NA) in children with suspected appendicitis. METHODS: A multicenter retrospective cohort analysis of children undergoing appendectomy for suspected appendicitis was performed using data from the 2016-2021 NSQIP-Pediatric Appendectomy Targeted Public Use Files. Multivariable regression was used to evaluate the influence of year, age, sex, and WBC count on NA rate, and to generate rate estimates for NA based on different combinations of demographic characteristics and WBC profiles. RESULTS: 100,322 patients were included from 140 hospitals. The overall NA rate was 2.4%, and rates decreased significantly during the study period (2016: 3.1% vs. 2021: 2.3%, p < 0.001). In adjusted analyses, the highest risk for NA was associated with a normal WBC (<9000/mm3; OR 5.31 [95% CI: 4.87-5.80]), followed by female sex (OR 1.55 [95% CI: 1.42-1.68]) and age <5 years (OR 1.64 [95% CI 1.39, 1.94]). Model-estimated risk for NA varied significantly across demographic and WBC strata, with a 14.4-fold range in rates between subgroups with the lowest and highest predicted risk (males 13-17 years with elevated WBC [1.1%] vs. females 3-4 years with normal WBC [15.8%]). CONCLUSIONS: Contemporary NA rates have decreased over time, however NA risk remains high in children without a leukocytosis, particularly for girls and children <5 years of age. These data provide contemporary performance benchmarks for NA in children with suspected appendicitis and identify high-risk populations where further efforts to mitigate NA risk should be targeted. LEVEL OF EVIDENCE: III.