Clinical prediction models for young febrile infants at the emergency department: an international validation study

Systematic review and meta-analysis assessing the diagnostic test accuracy of procalcitonin in the diagnosis of invasive bacterial infections in febrile infants: a study protocol

INTRODUCTION

Young febrile infants are at higher risk of invasive bacterial infections (IBIs) compared with older children. The clinical features of IBI are subtle in this cohort mandating that clinicians take a cautious approach to their initial assessment and management. This includes the measurement of blood biomarkers of infection such as C reactive protein (CRP) and procalcitonin (PCT). In the UK, PCT is not widely available and not recommended for routine use in hospital. This is in contrast to Europe and the USA where PCT is regularly used to assist clinical decision-making. The objective of this review and meta-analysis is to report the diagnostic test accuracy of PCT in detecting IBI in febrile infants less than 91 days old, compare its accuracy with CRP and define optimal PCT cut-off values in this cohort.

METHODS AND ANALYSIS

A search strategy will include MEDLINE, EMBASE, Web of Science, The Cochrane Library and grey literature. There will be no language or date limitations. Diagnostic accuracy studies compliant with STARD criteria will be considered against eligibility criteria. Abstracts, then full texts, of potentially eligible studies will be independently screened for selection. Data extraction and quality assessment, using the QUADAS-2 tool, will be completed by two independent authors and a third author used for any inconsistencies. True positives, false positives, true negatives and false negatives will be pooled to collate specificity and sensitivity with 95% CIs. Results will be portrayed in forest plots, alongside their quality assessments.

ETHICS AND DISSEMINATION

This review does not require ethical clearance. This review will be published in peer-reviewed journals and key messages will be disseminated through presentations at local and international conferences related to this field. The authors aim for this review to be completed and published in 2023.

Integrating Clinical Signs at Presentation and Clinician's Non-analytical Reasoning in Prediction Models for Serious Bacterial Infection in Febrile Children Presenting to Emergency Department

OBJECTIVE

Development and validation of clinical prediction model (CPM) for serious bacterial infections (SBIs) in children presenting to the emergency department (ED) with febrile illness, based on clinical variables, clinician's "gut feeling," and "sense of reassurance.

MATERIALS AND METHODS

Febrile children presenting to the ED of Children's Clinical University Hospital (CCUH) between April 1, 2017 and December 31, 2018 were enrolled in a prospective observational study. Data on clinical signs and symptoms at presentation, together with clinician's "gut feeling" of something wrong and "sense of reassurance" were collected as candidate variables for CPM. Variable selection for the CPM was performed using stepwise logistic regression (forward, backward, and bidirectional); Akaike information criterion was used to limit the number of parameters and simplify the model. Bootstrapping was applied for internal validation. For external validation, the model was tested in a separate dataset of patients presenting to six regional hospitals between January 1 and March 31, 2019.

RESULTS

The derivation cohort consisted of 517; 54% (n = 279) were boys, and the median age was 58 months. SBI was diagnosed in 26.7% (n = 138). Validation cohort included 188 patients; the median age was 28 months, and 26.6% (n = 50) developed SBI. Two CPMs were created, namely, CPM1 consisting of six clinical variables and CPM2 with four clinical variables plus "gut feeling" and "sense of reassurance." The area under the curve (AUC) for receiver operating characteristics (ROC) curve of CPM1 was 0.744 (95% CI, 0.683-0.805) in the derivation cohort and 0.692 (95% CI, 0.604-0.780) in the validation cohort. AUC for CPM2 was 0.783 (0.727-0.839) and 0.752 (0.674-0.830) in derivation and validation cohorts, respectively. AUC of CPM2 in validation population was significantly higher than that of CPM1 [p = 0.037, 95% CI (-0.129; -0.004)]. A clinical evaluation score was derived from CPM2 to stratify patients in "low risk," "gray area," and "high risk" for SBI.

CONCLUSION

Both CPMs had moderate ability to predict SBI and acceptable performance in the validation cohort. Adding variables "gut feeling" and "sense of reassurance" in CPM2 improved its ability to predict SBI. More validation studies are needed for the assessment of applicability to all febrile patients presenting to ED.

Limited Utility of SIRS Criteria for Identifying Serious Infections in Febrile Young Infants

(1) Background: Young infants have a high risk of serious infection. The Systematic Inflammatory Response Syndrome (SIRS) criteria can be useful to identify both serious bacterial and viral infections. The aims of this study were to evaluate the diagnostic performance of the SIRS criteria for identifying serious infections in febrile young infants and to identify potential clinical predictors of such infections. (2) Methods: We conducted this prospective cohort study including febrile young infants (aged < 90 days) seen at the emergency department with a body temperature of 38.0 °C or higher. We calculated the diagnostic performance parameters and conducted the logistic regression analysis to identify the predictors of serious infection. (3) Results: Of 311 enrolled patients, 36.7% (n = 114) met the SIRS criteria and 28.6% (n = 89) had a serious infection. The sensitivity, specificity, positive predictive value, and positive likelihood ratio of the SIRS criteria for serious infection was 45.9%, 69.4%, 43.5%, 71.4%, 1.5, and 0.8, respectively. Logistic regression showed that male gender, body temperature ≥ 38.5 °C, heart rate ≥ 178 bpm, and age ≤ 50 days were significant predictors. (4) Conclusions: The performance of the SIRS criteria for predicting serious infections among febrile young infants was poor.

Development and validation of a prediction model for invasive bacterial infections in febrile children at European Emergency Departments: MOFICHE, a prospective observational study

OBJECTIVES

To develop and cross-validate a multivariable clinical prediction model to identify invasive bacterial infections (IBI) and to identify patient groups who might benefit from new biomarkers.

DESIGN

Prospective observational study.

SETTING

12 emergency departments (EDs) in 8 European countries.

PATIENTS

Febrile children aged 0-18 years.

MAIN OUTCOME MEASURES

IBI, defined as bacteraemia, meningitis and bone/joint infection. We derived and cross-validated a model for IBI using variables from the Feverkidstool (clinical symptoms, C reactive protein), neurological signs, non-blanching rash and comorbidity. We assessed discrimination (area under the receiver operating curve) and diagnostic performance at different risk thresholds for IBI: sensitivity, specificity, negative and positive likelihood ratios (LRs).

RESULTS

Of 16 268 patients, 135 (0.8%) had an IBI. The discriminative ability of the model was 0.84 (95% CI 0.81 to 0.88) and 0.78 (95% CI 0.74 to 0.82) in pooled cross-validations. The model performed well for the rule-out threshold of 0.1% (sensitivity 0.97 (95% CI 0.93 to 0.99), negative LR 0.1 (95% CI 0.0 to 0.2) and for the rule-in threshold of 2.0% (specificity 0.94 (95% CI 0.94 to 0.95), positive LR 8.4 (95% CI 6.9 to 10.0)). The intermediate thresholds of 0.1%-2.0% performed poorly (ranges: sensitivity 0.59-0.93, negative LR 0.14-0.57, specificity 0.52-0.88, positive LR 1.9-4.8) and comprised 9784 patients (60%).

CONCLUSIONS

The rule-out threshold of this model has potential to reduce antibiotic treatment while the rule-in threshold could be used to target treatment in febrile children at the ED. In more than half of patients at intermediate risk, sensitive biomarkers could improve identification of IBI and potentially reduce unnecessary antibiotic prescriptions.

Accuracy of PECARN rule for predicting serious bacterial infection in infants with fever without a source

OBJECTIVE

To validate the Febrile Infant Working Group of the Pediatric Emergency Care Applied Research Network (PECARN) clinical prediction rule on an independent cohort of infants with fever without a source (FWS).

DESIGN

Secondary analysis of a prospective registry.

SETTING

Paediatric emergency department of a tertiary teaching hospital.

PATIENTS

Infants ≤60 days old with FWS between 2007 and 2018.

MAIN OUTCOME MEASURES

Prevalence of serious bacterial infection (SBI) and invasive bacterial infection (IBI) in low-risk infants according to the PECARN rule.

RESULTS

Among the 1247 infants included, 256 were diagnosed with an SBI (20.5%), including 38 IBIs (3.1%). Overall, 576 infants (46.0%; 95% CI 43.4% to 49.0%) would have been classified as low risk of SBI by the PECARN rule. Of them, 26 had an SBI (4.5%), including 5 with an IBI (2 (0.8%) diagnosed with bacterial meningitis). Sensitivity and specificity of the PECARN rule were 89.8% (95% CI 85.5% to 93.0%) and 55.5% (95% CI 52.4% to 58.6%) for SBI, with an area under the curve of 0.726 (95% CI 0.702 to 0.750). Its sensitivity to identify SBIs was 88.6% (95% CI 82.0% to 92.9%) among infants with a <6-hour history of fever (54.9% of the infants included).

CONCLUSIONS

The PECARN clinical rule for identifying SBI performed less well in our population than in the original study. This clinical rule should be applied cautiously in young infants with a short history of fever.

Assessment of the impact of a new sequential approach to antimicrobial use in young febrile children in the emergency department (DIAFEVERCHILD): a French prospective multicentric controlled, open, cluster-randomised, parallel-group study protocol

INTRODUCTION

Fever is one of the most common reasons for consultation in the paediatric emergency department (ED). Because of fear of bacterial infection in parents and caregivers, clinicians often overprescribe laboratory tests and empirical antibiotic treatment. The aims of this study are to demonstrate that using a procalcitonin (PCT) rapid test-based prediction rule (1) would not be inferior to usual practice in terms of morbidity and mortality (non-inferiority objective) and (2) would result in a significant reduction in antibiotic use (superiority objective).

METHODS AND ANALYSIS

This prospective multicentric cluster-randomised study aims to include 7245 febrile children aged 6 days to 3 years with a diagnosis of fever without source in 26 participating EDs in France and Switzerland during a 24-month period. During first period, all children will receive usual care. In a second period, a point-of-care PCT-based algorithm will be used in half of the clusters. The primary endpoints collected on day 15 after ED consultation will be a composite outcome of death or intensive care unit admission for any reason, disease-specific complications, diagnosis of bacterial infection after discharge from the ED for the non-inferiority objective and proportion of children with antibiotic treatment administered for the superiority objective. The endpoints will be compared between the two groups (experimental and control) by using a mixed logistic regression model adjusted on clustering of participants within centres and period within centres.

DISCUSSION

If the algorithm is validated, a new strategy will be discussed with medical societies to safely manage fever in young children without the need for invasive procedures for microbiological testing or empirical antibiotics.

ETHICS AND DISSEMINATION

This study was submitted to an independent ethics committee on 17 May 2018 (no. 2018-A00252-53). Results will be submitted to international peer-reviewed journals and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT03607162; Pre-results.

FeBRILe3 Project: protocol for a prospective pragmatic, multisite observational study and safety evaluation assessing Fever, Blood cultures and Readiness for discharge in Infants Less than 3 months old

INTRODUCTION

The purpose of this observational study is to assess the safety and impact of the introduction of a clinical practice guideline (CPG) recommending early discharge of infants with fever without source who are at low risk of serious bacterial infection (SBI). We hypothesise that implementation of this guideline will be associated with a rate of unplanned readmission to hospital (within 7 days of discharge) which is similar (ie, non-inferior) to that observed under previous standard practice.

METHODS AND ANALYSIS

This observational study is a prospective pragmatic, multisite safety assessment and impact project. It will evaluate the safety of a CPG which allows febrile infants fulfilling low-risk criteria to be discharged early from hospital if their blood cultures demonstrate no growth at 24 hours (compared with previous minimum 48 hours admission). This guideline has been implemented at two Western Australian metropolitan hospitals. Infants aged <3 months (chronological or corrected for premature birth before 37 weeks gestation) presenting with fever without source will be included. The primary outcome is readmission to hospital due to clinical deterioration/caregiver concern within 7 days of discharge, identified through review of electronic admission details and study-specific caregiver surveys. Secondary outcomes include rates of SBI, hospital lengths of stay compared with previous practice, clinician guideline adherence and caregiver satisfaction with the discharge process. Analysis will be within a sequential Bayesian safety monitoring framework, which incorporates new information and updates the evidence for guideline safety relative to previous practice (historical control) at prespecified interim analyses. Demographic and clinical information will be summarised.

ETHICS AND DISSEMINATION

Ethics approval and waiver of consent for data collection has been granted by the Child and Adolescent Health Service Human Research Ethics Committee (RGS0000001415). Caregivers will have the option to opt out of survey follow-up. Results will be disseminated via peer-reviewed publication.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12619001010189).