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The Influence of Age on the Diagnostic Performance of White Blood Cell Count and Absolute Neutrophil Count in Suspected Pediatric Appendicitis
Author(s) -
Bachur Richard G.,
Dayan Peter S.,
Dudley Nanette C.,
Bajaj Lalit,
Stevenson Michelle D.,
Macias Charles G.,
Mittal Manoj K.,
Bennett Jonathan,
Sinclair Kelly,
Monuteaux Michael C.,
Kharbanda Anupam B.
Publication year - 2016
Publication title -
academic emergency medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.221
H-Index - 124
eISSN - 1553-2712
pISSN - 1069-6563
DOI - 10.1111/acem.13018
Subject(s) - medicine , white blood cell , absolute neutrophil count , interquartile range , confidence interval , receiver operating characteristic , complete blood count , gastroenterology , prospective cohort study , neutropenia , toxicity
Objective White blood cell ( WBC ) count and absolute neutrophil count ( ANC ) are a standard part of the evaluation of suspected appendicitis. Specific threshold values are utilized in clinical pathways, but the discriminatory value of WBC count and ANC may vary by age. The objective of this study was to investigate whether the diagnostic value of WBC count and ANC varies across age groups and whether diagnostic thresholds should be age‐adjusted. Methods This is a multicenter prospective observational study of patients aged 3–18 years who were evaluated for appendicitis. Receiver operator characteristic curves were developed to assess overall discriminative power of WBC count and ANC across three age groups: <5, 5–11, and 12–18 years of age. Diagnostic performance of WBC count and ANC was then assessed at specific cut‐points. Results A total of 2,133 patients with a median age of 10.9 years (interquartile range = 8.0–13.9 years) were studied. Forty‐one percent had appendicitis. The area under the curve ( AUC ) for WBC count was 0.69 (95% confidence interval [ CI ] = 0.61 to 0.77) for patients < 5 years of age, 0.76 (95% CI = 0.73 to 0.79) for 5–11 years of age, and 0.83 (95% CI = 0.81 to 0.86) for 12–18 years of age. The AUC s for ANC across age groups mirrored WBC performance. At a commonly utilized WBC cut‐point of 10,000/mm 3 , the sensitivity decreased with increasing age: 95% (<5 years), 91% (5–11 years), and 89% (12–18 years) whereas specificity increased by age: 36% (<5 years), 49% (5–12 years), and 64% (12–18 years). Conclusion WBC count and ANC had better diagnostic performance with increasing age. Age‐adjusted values of WBC count or ANC should be considered in diagnostic strategies for suspected pediatric appendicitis.