Triage Performance and Physiological Predictors of Serious Illness in Febrile Children in the Pediatric Emergency Department

Overview

This multicenter prospective observational cohort study evaluates how well the initial triage category assigned by the Turkish Ministry of Health three-level color-coded triage system (Red-Yellow-Green) predicts serious clinical outcomes in children aged 0-18 years who present with fever to pediatric emergency departments. The study additionally assesses whether physiological parameters recorded at triage (heart rate, respiratory rate, oxygen saturation, capillary refill time, AVPU level of consciousness, and general appearance) provide independent and incremental prognostic value beyond the assigned triage category. Ten centers across Turkey will enroll consecutive eligible febrile children over a 3-month period. Routine clinical care and triage decisions are not altered by the study. The primary outcome is a composite serious clinical outcome. The study is reported in accordance with the STROBE and TRIPOD statements.

Design: Prospective, multicenter, observational cohort study. Setting: 10 pediatric emergency departments in Turkey; Erciyes University is the coordinating center. Population: consecutive children aged 0-18 years presenting with fever (\>=38.0 C at triage or history of fever within the preceding 24 hours). Trauma presentations, elective visits, records with missing triage data, and re-attendances within 72 hours for the same episode are excluded (only the first visit is included). Physiological parameters are recorded on a standardized triage form and are NOT used to change the triage decision. Heart rate is modeled as a continuous variable with age-based z-scores (Fleming reference ranges), with body temperature always included as a covariate to distinguish fever-related from pathological tachycardia. Sample size: assuming a serious-outcome (composite) event rate of \~3%, approximately 3000 children (\~90 events) are targeted (\~300 per center over 3 months), following Riley et al. (BMJ 2020) criteria (target R2\>=0.15, calibration slope\>=0.90) in addition to the EPV\>=10 rule. A pilot evaluation at the end of the first month recalculates the true event rate. Analysis: Triage performance is summarized with sensitivity, specificity, PPV, NPV, LR+ and LR- with 95% CIs. A pre-specified 3-step mixed-effects logistic regression (centers as random effect) compares Model 1 (triage category only), Model 2 (+ physiological parameters and temperature), and Model 3 (+ laboratory variables in the tested subgroup). Discrimination (ROC/AUC, DeLong test, NRI, IDI) and calibration (calibration curve and slope, O/E ratio) are reported. Missing data are handled by multiple imputation (m=20).