A rapid host-protein test for differentiating bacterial from viral infection: Apollo diagnostic accuracy study.

Objectives: To determine the diagnostic accuracy of a rapid host-protein test for differentiating bacterial from viral infections in patients who presented to the emergency department (ED) or urgent care center (UCC). Methods: This was a prospective multicenter, blinded study. MeMed BV (MMBV), a test based on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), interferon gamma-inducible protein-10 (IP-10), and C-reactive protein (CRP), was measured using a rapid measurement platform. Patients were enrolled from 9 EDs and 3 UCCs in the United States and Israel. Patients >3 months of age presenting with fever and clinical suspicion of acute infection were considered eligible. MMBV results were not provided to the treating clinician. MMBV results (bacterial/viral/equivocal) were compared against a reference standard method for classification of infection etiology determined by expert panel adjudication. Experts were blinded to MMBV results. They were provided with comprehensive patient data, including laboratory, microbiological, radiological and follow-up. Results: Of 563 adults and children enrolled, 476 comprised the study population (314 adults, 162 children). The predominant clinical syndrome was respiratory tract infection (60.5% upper, 11.3% lower). MMBV demonstrated sensitivity of 90.0% (95% confidence interval [CI]: 80.3-99.7), specificity of 92.8% (90.0%-95.5%), and negative predictive value of 98.8% (96.8%-99.6%) for bacterial infections. Only 7.2% of cases yielded equivocal MMBV scores. Area under the curve for MMBV was 0.95 (0.90-0.99). Conclusions: MMBV had a high sensitivity and specificity relative to reference standard for differentiating bacterial from viral infections. Future implementation of MMBV for patients with suspected acute infections could potentially aid with appropriate antibiotic decision-making.

Emergency Department Volume and Delayed Diagnosis of Serious Pediatric Conditions.

Importance: Diagnostic delays are common in the emergency department (ED) and may predispose to worse outcomes. Objective: To evaluate the association of annual pediatric volume in the ED with delayed diagnosis. Design, Setting, and Participants: This retrospective cohort study included all children younger than 18 years treated at 954 EDs in 8 states with a first-time diagnosis of any of 23 acute, serious conditions: bacterial meningitis, compartment syndrome, complicated pneumonia, craniospinal abscess, deep neck infection, ectopic pregnancy, encephalitis, intussusception, Kawasaki disease, mastoiditis, myocarditis, necrotizing fasciitis, nontraumatic intracranial hemorrhage, orbital cellulitis, osteomyelitis, ovarian torsion, pulmonary embolism, pyloric stenosis, septic arthritis, sinus venous thrombosis, slipped capital femoral epiphysis, stroke, or testicular torsion. Patients were identified using the Healthcare Cost and Utilization Project State ED and Inpatient Databases. Data were collected from January 2015 to December 2019, and data were analyzed from July to December 2023. Exposure: Annual volume of children at the first ED visited. Main Outcomes and Measures: Possible delayed diagnosis, defined as a patient with an ED discharge within 7 days prior to diagnosis. A secondary outcome was condition-specific complications. Rates of possible delayed diagnosis and complications were determined. The association of volume with delayed diagnosis across conditions was evaluated using conditional logistic regression matching on condition, age, and medical complexity. Condition-specific volume-delay associations were tested using hierarchical logistic models with log volume as the exposure, adjusting for age, sex, payer, medical complexity, and hospital urbanicity. The association of delayed diagnosis with complications by condition was then examined using logistic regressions. Results: Of 58 998 included children, 37 211 (63.1%) were male, and the mean (SD) age was 7.1 (5.8) years. A total of 6709 (11.4%) had a complex chronic condition. Delayed diagnosis occurred in 9296 (15.8%; 95% CI, 15.5-16.1). Each 2-fold increase in annual pediatric volume was associated with a 26.7% (95% CI, 22.5-30.7) decrease in possible delayed diagnosis. For 21 of 23 conditions (all except ectopic pregnancy and sinus venous thrombosis), there were decreased rates of possible delayed diagnosis with increasing ED volume. Condition-specific complications were 11.2% (95% CI, 3.1-20.0) more likely among patients with a possible delayed diagnosis compared with those without. Conclusions and Relevance: EDs with fewer pediatric encounters had more possible delayed diagnoses across 23 serious conditions. Tools to support timely diagnosis in low-volume EDs are needed.

Interpretation of Antibiotic Trials in Pediatric Pneumonia.

This cohort study assesses radiographic evidence of pneumonia and antibiotic use in children with clinically suspected community-acquired pneumonia.

Disparities in Diagnostic Timeliness and Outcomes of Pediatric Appendicitis.

This cohort study compares rates of delayed diagnosis and complications of appendicitis by race and ethnicity and Child Opportunity Index among children in 8 states.

Critical Emergency Department Interventions and Clinical Deterioration in Children With Nonsevere Traumatic Intracranial Hemorrhage.

OBJECTIVE: Substantial practice variation exists in the management of children with nonsevere traumatic intracranial hemorrhage (tICH). A comprehensive understanding of rates and timing of clinically important tICH, including critical interventions and deterioration, along with associated clinical and neuroradiographic characteristics, will inform accurate risk stratification. METHODS: We conducted a single-center retrospective cohort study of children aged younger than 18 years evaluated in the emergency department (ED) from May 1, 2014 to February 28, 2020 with tICH and initial Glasgow Coma Scale (GCS) score of higher than 8. We determined rates of clinically important tICH after injury and within 96 hours of ED arrival, defined as immediate ED interventions (intubation, hyperosmotic agents, or neurosurgery within 4 hours of arrival) or clinically important deterioration (signs/symptoms with change in management). Associations between outcome and clinical and neuroradiographic characteristics were calculated using individual logistic regression models. RESULTS: Our sample included 135 children. Clinically important tICH was observed in 13.3% (n = 18); 9 (6.7%) underwent immediate ED interventions and 9 (6.7%) developed deterioration. Most (93.3%, n = 127) presented with an initial GCS ≥ 14, including all children who later deteriorated. Initial GCS (P = 0.001) and nonaccidental trauma (P = 0.024) mechanism were associated with the outcome. None of the 71 (52.6%) children with initial GCS ≥ 14, isolated, nonepidural hemorrhage after accidental injury developed clinically important tICH. CONCLUSIONS: Clinically important tICH occurred in 13% of children with nonsevere tICH, and 7% of children who did not undergo immediate ED interventions later deteriorated, all of whom had an initial GCS ≥ 14. However, a subgroup of children was identified as low risk based on clinical and neuroradiographic characteristics.

Community Validation of an Approach to Detect Delayed Diagnosis of Appendicitis in Big Databases.

BACKGROUND: Detection of delayed diagnosis using administrative databases may illuminate the healthcare settings at highest risk. A method for detection of delays in claims has been validated in children's hospitals. We sought to further validate the method in community emergency departments (EDs). METHODS: We studied patients <21 years old diagnosed with appendicitis from 2008 to 2019 in 8 eastern Massachusetts EDs. Eligible patients had 2 ED encounters within 7 days, the second with an appendicitis diagnosis. Delayed diagnosis was evaluated in medical records by trained reviewers. A previously validated trigger tool was applied to participants' electronic medical record data. The tool used data elements included in administrative data, including initial encounter diagnoses, time between encounters, presence of medical complexity, and ultimate length of stay. The tool assigned a probability of delayed diagnosis for each patient. Test characteristics at 4 confidence thresholds were determined, and the area under the receiver operating curve was calculated. RESULTS: We analyzed 68 children with 2 encounters leading to a diagnosis of appendicitis (i.e., possible delay). When assigning a delayed diagnosis prediction to patients at 4 thresholds of confidence (>0%, >50%, >75%, and >90% confident), the positive predictive values were respectively 74%, 89%, 92%, and 89%; the negative predictive values were respectively 100%, 57%, 50%, and 33%. The area under the receiver operating curve was 0.837 (95% confidence interval 0.719-0.954). CONCLUSIONS: A trigger tool that identifies delays in diagnosis using only administrative data in community EDs has a high positive predictive value for true delay. The tool may be applied in community EDs.

Multicenter evaluation of a method to identify delayed diagnosis of diabetic ketoacidosis and sepsis in administrative data.

OBJECTIVES: To derive a method of automated identification of delayed diagnosis of two serious pediatric conditions seen in the emergency department (ED): new-onset diabetic ketoacidosis (DKA) and sepsis. METHODS: Patients under 21 years old from five pediatric EDs were included if they had two encounters within 7 days, the second resulting in a diagnosis of DKA or sepsis. The main outcome was delayed diagnosis based on detailed health record review using a validated rubric. Using logistic regression, we derived a decision rule evaluating the likelihood of delayed diagnosis using only characteristics available in administrative data. Test characteristics at a maximal accuracy threshold were determined. RESULTS: Delayed diagnosis was present in 41/46 (89 %) of DKA patients seen twice within 7 days. Because of the high rate of delayed diagnosis, no characteristic we tested added predictive power beyond the presence of a revisit. For sepsis, 109/646 (17 %) of patients were deemed to have a delay in diagnosis. Fewer days between ED encounters was the most important characteristic associated with delayed diagnosis. In sepsis, our final model had a sensitivity for delayed diagnosis of 83.5 % (95 % confidence interval 75.2-89.9) and specificity of 61.3 % (95 % confidence interval 56.0-65.4). CONCLUSIONS: Children with delayed diagnosis of DKA can be identified by having a revisit within 7 days. Many children with delayed diagnosis of sepsis may be identified using this approach with low specificity, indicating the need for manual case review.

Emergency Department Volume and Delayed Diagnosis of Pediatric Appendicitis: A Retrospective Cohort Study.

OBJECTIVE: To determine the association of emergency department (ED) volume of children and delayed diagnosis of appendicitis. BACKGROUND: Delayed diagnosis of appendicitis is common in children. The association between ED volume and delayed diagnosis is uncertain, but diagnosis-specific experience might improve diagnostic timeliness. METHODS: Using Healthcare Cost and Utilization Project 8-state data from 2014 to 2019, we studied all children with appendicitis <18 years old in all EDs. The main outcome was probable delayed diagnosis: >75% likelihood that a delay occurred based on a previously validated measure. Hierarchical models tested associations between ED volumes and delay, adjusting for age, sex, and chronic conditions. We compared complication rates by delayed diagnosis occurrence. RESULTS: Among 93,136 children with appendicitis, 3,293 (3.5%) had delayed diagnosis. Each 2-fold increase in ED volume was associated with a 6.9% (95% CI: 2.2, 11.3) decreased odds of delayed diagnosis. Each 2-fold increase in appendicitis volume was associated with a 24.1% (95% CI: 21.0, 27.0) decreased odds of delay. Those with delayed diagnosis were more likely to receive intensive care [odds ratio (OR): 1.81, 95% CI: 1.48, 2.21], have perforated appendicitis (OR: 2.81, 95% CI: 2.62, 3.02), undergo abdominal abscess drainage (OR: 2.49, 95% CI: 2.16, 2.88), have multiple abdominal surgeries (OR: 2.56, 95% CI: 2.13, 3.07), or develop sepsis (OR: 2.02, 95% CI: 1.61, 2.54). CONCLUSIONS: Higher ED volumes were associated with a lower risk of delayed diagnosis of pediatric appendicitis. Delay was associated with complications.

OUTCOMES OF MISSED DIAGNOSIS OF PEDIATRIC APPENDICITIS, NEW-ONSET DIABETIC KETOACIDOSIS, AND SEPSIS IN FIVE PEDIATRIC HOSPITALS.

BACKGROUND: Missed diagnosis can predispose to worse condition-specific outcomes. OBJECTIVE: To determine 90-day complication rates and hospital utilization after a missed diagnosis of pediatric appendicitis, new-onset diabetic ketoacidosis (DKA), and sepsis. METHODS: We evaluated patients under 21 years of age visiting five pediatric emergency departments (EDs) with a study condition. Case patients had a preceding ED visit within 7 days of diagnosis and underwent case review to confirm a missed diagnosis. Control patients had no preceding ED visit. We compared complication rates and utilization between case and control patients after adjusting for age, sex, and insurance. RESULTS: We analyzed 29,398 children with appendicitis, 5366 with DKA, and 3622 with sepsis, of whom 429, 33, and 46, respectively, had a missed diagnosis. Patients with missed diagnosis of appendicitis or DKA had more hospital days and readmissions; there were no significant differences for those with sepsis. Those with missed appendicitis were more likely to have abdominal abscess drainage (adjusted odds ratio [aOR] 3.0, 95% confidence interval [CI] 2.4-3.6) or perforated appendicitis (aOR 3.1, 95% CI 2.5-3.8). Those with missed DKA were more likely to have cerebral edema (aOR 4.6, 95% CI 1.5-11.3), mechanical ventilation (aOR 13.4, 95% CI 3.8-37.1), or death (aOR 28.4, 95% CI 1.4-207.5). Those with missed sepsis were less likely to have mechanical ventilation (aOR 0.5, 95% CI 0.2-0.9). Other illness complications were not significantly different by missed diagnosis. CONCLUSIONS: Children with delayed diagnosis of appendicitis or new-onset DKA had a higher risk of 90-day complications and hospital utilization than those with a timely diagnosis.

Identification of delayed diagnosis of paediatric appendicitis in administrative data: a multicentre retrospective validation study.

OBJECTIVE: To derive and validate a tool that retrospectively identifies delayed diagnosis of appendicitis in administrative data with high accuracy. DESIGN: Cross-sectional study. SETTING: Five paediatric emergency departments (EDs). PARTICIPANTS: 669 patients under 21 years old with possible delayed diagnosis of appendicitis, defined as two ED encounters within 7 days, the second with appendicitis. OUTCOME: Delayed diagnosis was defined as appendicitis being present but not diagnosed at the first ED encounter based on standardised record review. The cohort was split into derivation (2/3) and validation (1/3) groups. We derived a prediction rule using logistic regression, with covariates including variables obtainable only from administrative data. The resulting trigger tool was applied to the validation group to determine area under the curve (AUC). Test characteristics were determined at two predicted probability thresholds. RESULTS: Delayed diagnosis occurred in 471 (70.4%) patients. The tool had an AUC of 0.892 (95% CI 0.858 to 0.925) in the derivation group and 0.859 (95% CI 0.806 to 0.912) in the validation group. The positive predictive value (PPV) for delay at a maximal accuracy threshold was 84.7% (95% CI 78.2% to 89.8%) and identified 87.3% of delayed cases. The PPV at a stricter threshold was 94.9% (95% CI 87.4% to 98.6%) and identified 46.8% of delayed cases. CONCLUSIONS: This tool accurately identified delayed diagnosis of appendicitis. It may be used to screen for potential missed diagnoses or to specifically identify a cohort of children with delayed diagnosis.

Boston Febrile Infant Algorithm 2.0: Improving Care of the Febrile Infant 1-2 Months of Age.

Significant variation exists in the management of febrile infants, particularly those between 1 and 2 months of age. An established algorithm for well-appearing febrile infants 1-2 months of age guided clinical care for three decades in our emergency department. With mounting evidence for procalcitonin (PCT) to detect invasive bacterial infection (IBI), we revised our algorithm intending to decrease lumbar punctures (LPs) and antibiotic administration without increasing hospitalizations, revisits, or missed IBI. Methods: The algorithm's risk stratification was revised based on the expert review of evidence regarding test performance of PCT for IBI in febrile infants. With the revision, routine LP and empiric antibiotics were not recommended for low-risk infants. We used quality improvement strategies to disseminate the revised algorithm and reinforce uptake. The primary outcomes were the proportion of infants undergoing lumbar punctures or receiving antibiotics. Admission rates, 72-hour revisits requiring admission, and missed IBI were monitored as balancing measures. Results: We studied 616 infants including 326 (52.9%), after the implementation of the revised algorithm. LP was performed in 66.2% prerevision and 31.9% postrevision (34.3% absolute reduction, P < 0.001). Antibiotic administration decreased by 26.2% (pre 62.4% to post 36.2%, P < 0.001) and hospitalization rates decreased by 8.1% (P = 0.03). There have been no missed IBIs. Adherence to the pathway led to a sustained reduction in LPs and antibiotic administration for 24 months. Conclusion: A revised pathway with the addition of PCT resulted in a safe, sustained reduction in LPs and reduced antibiotic administration in febrile infants 1-2 months of age.

Nonoperative Management of Uncomplicated Appendicitis.

BACKGROUND AND OBJECTIVES: Several studies have revealed the success of nonoperative management (NOM) of uncomplicated appendicitis in children. Large studies of current NOM utilization and its outcomes in children are lacking. METHODS: We queried the Pediatric Health Information System database to identify children <19 years of age with a diagnosis code for appendicitis. We used linear trend analysis to assess the subsequent utilization and outcomes of NOM in children with nonperforated appendicitis over time. We calculated the proportion of children experiencing treatment failure, defined as either a subsequent appendectomy or hospitalization with a diagnosis code of perforated appendicitis. RESULTS: We identified 117 705 children with appendicitis over the 9-year study period. Of the 73 544 children with nonperforated appendicitis, 10 394 (14.1%) underwent NOM. The odds of NOM significantly increased (odds ratio 1.10 per study quarter, 95% confidence interval [CI] 1.05-1.15). The 1-year and 5-year failure rates were 18.6% and 23.3%, respectively. Children who experienced failure of NOM had higher rates of perforation at the time of failure than did the general cohort at the time of initial presentation (45.7% vs 37.5%, P < .001). Patients undergoing NOM had higher rates of subsequent related emergency department visits (8.0% vs 5.1%, P < .001) and hospitalizations (4.2% vs 1.4%, P < .001) over a 12-month follow-up period. CONCLUSIONS: NOM of nonperforated appendicitis in children is increasing. Although the majority of children who undergo NOM remain recurrence-free years later, they carry a substantial risk of perforation at the time of recurrence and may experience a higher rate of postoperative complications than children undergoing an immediate appendectomy.

Severity of Illness in Bronchiolitis Amid Unusual Seasonal Pattern During the COVID-19 Pandemic.

OBJECTIVE: We aimed to characterize recent trends in bronchiolitis at US children's hospitals and to compare severity of illness in bronchiolitis in the most recent year to the previous seasonal epidemics. METHODS: This is a cross-sectional study of visits for bronchiolitis in infants <24 months old from October 2016 to September 2021 at 46 US children's hospitals participating in the Pediatric Health Information Systems database. Study years were defined by 12-month periods beginning in October to account for typical winter epidemics that crossover calendar years. We used logistic and Fourier Poisson regression models to examine trends in outcomes and compare seasonality, respectively. RESULTS: The study included 389 411 emergency visits for bronchiolitis. Median age of infants with bronchiolitis was higher in October 2020 to September 2021 compared to previous epidemics (8 and 6 months, respectively, P < .001) The odds of hospitalization, ICU admission, invasive mechanical ventilation, and noninvasive ventilation did not differ in October 2020 to September 2021 compared to previous epidemics from October 2016 to September 2020 (all P > .05 for unadjusted models and models adjusted for age). Seasonality varied significantly among these 2 periods (P < .001). CONCLUSIONS: Although the seasonality of bronchiolitis differed in October 2020 to September 2021, severity of illness in infants with bronchiolitis was consistent with previous epidemics.

Refining sonographic criteria for paediatric appendicitis: combined effects of age-based appendiceal size and secondary findings.

OBJECTIVE: Appendiceal diameter is a primary sonographic determinant of paediatric appendicitis. We sought to determine if the diagnostic performance of outer appendiceal diameter differs based on age or with the addition of secondary sonographic findings. METHODS: We retrospectively reviewed patients aged less than 19 years who presented to the Boston Children's Hospital ED and had an ultrasound (US) for the evaluation of appendicitis between November 2015 and October 2018. Our primary outcome was the presence of appendicitis. We analysed the cases to evaluate the optimal outer appendiceal diameter as a predictor for appendicitis stratified by age (<6, 6 to <11, 11 to <19 years), and with the addition of one or more secondary sonographic findings. RESULTS: Overall, 945 patients met criteria for inclusion, of which 43.9% had appendicitis. Overall, appendiceal diameter as a continuous measure demonstrated excellent test performance across all age groups (area under the curve (AUC) >0.95) but was most predictive of appendicitis in the youngest age group (AUC=0.99 (0.98-1.00)). Although there was no significant difference in optimal diameter threshold between age groups, both 7- and 8-mm thresholds were more predictive than 6 mm across all groups (p<0.001). The addition of individual (particularly appendicolith or echogenic fat) or combinations of secondary sonographic findings increased the diagnostic value for appendicitis above diameter alone. CONCLUSIONS: Appendiceal diameter as a continuous measure was more predictive of appendicitis in the youngest group. Across all age groups, the optimal diameter threshold was 7 mm for the diagnosis of paediatric appendicitis. The addition of individual or combination secondary sonographic findings increases diagnostic performance.

Significance of Sonographic Subcentimeter, Subpleural Consolidations in Pediatric Patients Evaluated for Pneumonia.

OBJECTIVES: To investigate the rates of radiographic pneumonia and clinical outcomes of children with suspected pneumonia and subcentimeter, subpleural consolidations on point-of-care lung ultrasound. STUDY DESIGN: We enrolled a prospective convenience sample of children aged 6 months to 18 years undergoing chest radiography (CXR) for pneumonia evaluation in a single tertiary-care pediatric emergency department. Point-of-care lung ultrasound was performed by an emergency medicine physician with subsequent expert review. We determined rates of radiographic pneumonia and clinical outcomes in the children with subcentimeter, subpleural consolidations, stratified by the presence of larger (>1 cm) sonographic consolidations. The children were followed prospectively for 2 weeks to identify a delayed diagnosis of pneumonia. RESULTS: A total of 188 patients, with a median age of 5.8 years (IQR, 3.5-11.0 years), were evaluated. Of these patients, 62 (33%) had subcentimeter, subpleural consolidations on lung ultrasound, and 23 (37%) also had larger (>1 cm) consolidations. Patients with subcentimeter, subpleural consolidations and larger consolidations had the highest rates of definite radiographic pneumonia (61%), compared with 21% among children with isolated subcentimeter, subpleural consolidations. Overall, 23 children with isolated subcentimeter, subpleural consolidations (59%) had no evidence of pneumonia on CXR. Among 16 children with isolated subcentimeter, subpleural consolidations and not treated with antibiotics, none had a subsequent pneumonia diagnosis within the 2-week follow-up period. CONCLUSIONS: Children with subcentimeter, subpleural consolidations often had radiographic pneumonia; however, this occurred most frequently when subcentimeter, subpleural consolidations were identified in combination with larger consolidations. Isolated subcentimeter, subpleural consolidations in the absence of larger consolidations should not be viewed as synonymous with pneumonia; CXR may provide adjunctive information in these cases.

Development of the Novel Pneumonia Risk Score to Predict Radiographic Pneumonia in Children.

BACKGROUND: The diagnosis of pneumonia in children is challenging, given the wide overlap of many of the symptoms and physical examination findings with other common respiratory illnesses. We sought to derive and validate the novel Pneumonia Risk Score (PRS), a clinical tool utilizing signs and symptoms available to clinicians to determine a child's risk of radiographic pneumonia. METHODS: We prospectively enrolled children 3 months to 18 years in whom a chest radiograph (CXR) was obtained in the emergency department to evaluate for pneumonia. Before CXR, we collected information regarding symptoms, physical examination findings, and the physician-estimated probability of radiographic pneumonia. Logistic regression was used to predict the presence of radiographic pneumonia, and the PRS was validated in a distinct cohort of children with suspected pneumonia. RESULTS: Among 1181 children included in the study, 206 (17%) had radiographic pneumonia. The PRS included age in years, triage oxygen saturation, presence of fever, presence of rales, and presence of wheeze. The area under the curve (AUC) of the PRS was 0.71 (95% confidence interval [CI]: 0.68-0.75), while the AUC of clinician judgment was 0.61 (95% CI: 0.56-0.66) (P < 0.001). Among 2132 children included in the validation cohort, the PRS demonstrated an AUC of 0.69 (95% CI: 0.65-0.73). CONCLUSIONS: In children with suspected pneumonia, the PRS is superior to clinician judgment in predicting the presence of radiographic pneumonia. Use of the PRS may help efforts to support the judicious use of antibiotics and chest radiography among children with suspected pneumonia.

Trends in ED Resource Use for Infants 0 to 60 Days Evaluated for Serious Bacterial Infection.

OBJECTIVES: We examined trends in resource use for infants undergoing emergency department evaluation for serious bacterial infection, including lumbar puncture (LP), antibiotic administration, hospitalization, and procalcitonin testing, as well as the association between procalcitonin testing and LP, administration of parenteral antibiotics, and hospitalization. METHODS: We performed a cross-sectional study of infants aged 0 to 60 days who underwent emergency department evaluation for serious bacterial infection with blood and urine cultures from 2010 to 2019 in 27 hospitals in the Pediatric Health Information System. We examined temporal trends in LP, antibiotic administration, hospitalization, and procalcitonin testing from 2010 to 2019. We also estimated multivariable logistic regression models for 2017-2019, adjusted for demographic factors and stratified by age (<28 and 29-60 days), with LP, antibiotic administration, and hospitalization as dependent variables and hospital-level procalcitonin testing as the independent variable. RESULTS: We studied 106 547 index visits. From 2010 to 2019, rates of LP, antibiotic administration, and hospitalization decreased more for infants aged 29 to 60 days compared with infants aged 0 to 28 days (annual decrease in odds of LP, antibiotics administration, and hospitalization: 0 to 28 days: 5%, 5%, and 3%, respectively; 29-60 days: 15%, 12%, and 7%, respectively). Procalcitonin testing increased significantly each calendar year (odds ratio per calendar year 2.19; 95% confidence interval 1.82-2.62), with the majority (91.1%) performed during 2017-2019. From 2017 to 2019, there was no association between hospital-level procalcitonin testing and any outcome studied (all P values > .05). CONCLUSIONS: Rates of LP, antibiotic administration, and hospitalization decreased significantly for infants 29 to 60 days during 2010-2019. Although procalcitonin testing increased during 2017-2019, we found no association with hospital-level procalcitonin testing and patterns of resource use.

Clinical Features and Preventability of Delayed Diagnosis of Pediatric Appendicitis.

Importance: Delayed diagnosis of appendicitis is associated with worse outcomes than timely diagnosis, but clinical features associated with diagnostic delay are uncertain, and the extent to which delays are preventable is unclear. Objective: To determine clinical features associated with delayed diagnosis of pediatric appendicitis, assess the frequency of preventable delay, and compare delay outcomes. Design, Setting, and Participants: This case-control study included 748 children treated at 5 pediatric emergency departments in the US between January 1, 2010, and December 31, 2019. Participants were younger than 21 years and had a diagnosis of appendicitis. Exposures: Individual features of appendicitis and pretest likelihood of appendicitis were measured by the Pediatric Appendicitis Risk Calculator (pARC). Main Outcomes and Measures: Case patients had a delayed diagnosis of appendicitis, defined as 2 emergency department visits leading to diagnosis and a case review showing the patient likely had appendicitis at the first visit. Control patients had a single emergency department visit yielding a diagnosis. Clinical features and pARC scores were compared by case-control status. Preventability of delay was assessed as unlikely, possible, or likely. The proportion of children with indicated imaging based on an evidence-based cost-effectiveness threshold was determined. Outcomes of delayed diagnosis were compared by case-control status, including hospital length of stay, perforation, and multiple surgical procedures. Results: A total of 748 children (mean [SD] age, 10.2 [4.3] years; 392 boys [52.4%]; 427 White children [57.1%]) were included in the study; 471 (63.0%) had a delayed diagnosis of appendicitis, and 277 (37.0%) had no delay in diagnosis. Children with a delayed diagnosis were less likely to have pain with walking (adjusted odds ratio [aOR], 0.16; 95% CI, 0.10-0.25), maximal pain in the right lower quadrant (aOR, 0.12; 95% CI, 0.07-0.19), and abdominal guarding (aOR, 0.33; 95% CI, 0.21-0.51), and were more likely to have a complex chronic condition (aOR, 2.34; 95% CI, 1.05-5.23). The pretest likelihood of appendicitis was 39% to 52% lower in children with a delayed vs timely diagnosis. Among children with a delayed diagnosis, 109 cases (23.1%) were likely to be preventable, and 247 (52.4%) were possibly preventable. Indicated imaging was performed in 104 (22.0%) to 289 (61.3%) children with delayed diagnosis, depending on the imputation method for missing data on white blood cell count. Patients with delayed diagnosis had longer hospital length of stay (mean difference between the groups, 2.8 days; 95% CI, 2.3-3.4 days) and higher perforation rates (OR, 7.8; 95% CI, 5.5-11.3) and were more likely to undergo 2 or more surgical procedures (OR, 8.0; 95% CI, 2.0-70.4). Conclusions and Relevance: In this case-control study, delayed appendicitis was associated with initially milder symptoms but worse outcomes. These findings suggest that a majority of delayed diagnoses were at least possibly preventable and that many of these patients did not undergo indicated imaging, suggesting an opportunity to prevent delayed diagnosis of appendicitis in some children.