Novel Claims-Based Outcome Phenotypes in Survivors of Pediatric Traumatic Brain Injury

Discovery of Generalizable TBI Phenotypes Using Multivariate Time-Series Clustering

Traumatic Brain Injury (TBI) presents a broad spectrum of clinical presentations and outcomes due to its inherent heterogeneity, leading to diverse recovery trajectories and varied therapeutic responses. While many studies have delved into TBI phenotyping for distinct patient populations, identifying TBI phenotypes that consistently generalize across various settings and populations remains a critical research gap. Our research addresses this by employing multivariate time-series clustering to unveil TBI's dynamic intricates. Utilizing a self-supervised learning-based approach to clustering multivariate time-Series data with missing values (SLAC-Time), we analyzed both the research-centric TRACK-TBI and the real-world MIMIC-IV datasets. Remarkably, the optimal hyperparameters of SLAC-Time and the ideal number of clusters remained consistent across these datasets, underscoring SLAC-Time's stability across heterogeneous datasets. Our analysis revealed three generalizable TBI phenotypes (α, β, and γ), each exhibiting distinct non-temporal features during emergency department visits, and temporal feature profiles throughout ICU stays. Specifically, phenotype α represents mild TBI with a remarkably consistent clinical presentation. In contrast, phenotype β signifies severe TBI with diverse clinical manifestations, and phenotype γ represents a moderate TBI profile in terms of severity and clinical diversity. Age is a significant determinant of TBI outcomes, with older cohorts recording higher mortality rates. Importantly, while certain features varied by age, the core characteristics of TBI manifestations tied to each phenotype remain consistent across diverse populations.

Post-discharge rehabilitation and functional recovery after pediatric injury

INTRODUCTION

Variability in rehabilitation disposition has been proposed as a trauma center quality metric. Benchmarking rehabilitation disposition is limited by a lack of objective measures of functional impairment at discharge. The primary aim of this study was to determine the relative contribution of patient characteristics and hospitalization factors associated with inpatient and outpatient rehabilitation after discharge. The secondary aims were to evaluate the sensitivity of the Functional Status Scale (FSS) score for identifying functional impairments at hospital discharge and track post-discharge recovery.

PATIENTS AND METHODS

We report a planned secondary analysis of a prospective observational study of seriously injured children (<15 years old) enrolled at seven pediatric trauma centers. Functional Status Scale (FSS) score was measured for pre-injury, hospital discharge, and 6-month follow-up timepoints. Multinomial logistic regression identified factors associated with three dispositions: home without rehabilitation services, home with outpatient rehabilitation, and inpatient rehabilitation. Relative weight analysis was used to identify the impact of individual factors associated with inpatient or outpatient rehabilitation disposition.

RESULTS

We analyzed 427 children with serious injuries. Functional impairment at discharge was present in 103 (24.1%) children, including 43/337 (12.8%) discharged without services, 12/38 (31.6%) discharged with outpatient rehabilitation, and 44/47 (93.6%) discharged to inpatient rehabilitation. In multivariable modeling, variables most contributing to prediction of inpatient rehabilitation were severe initial Glasgow coma scale (GCS), injured body region, and functional impairment at discharge. Severe initial GCS, private insurance, and extremity injury were independently associated with disposition with outpatient rehabilitation. Patients discharged without services or with outpatient rehabilitation most frequently had motor impairments that improved during the next 6 months. Patients discharged to inpatient rehabilitation had impairments in all domains, with many improving within 6 months. A higher proportion of patients discharged to inpatient rehabilitation had residual impairments at follow-up.

CONCLUSION

Injury characteristics and discharge impairment were associated with discharge to inpatient rehabilitation. The FSS score identified impairments needing inpatient rehabilitation and characterized improvements after discharge. Less severe impairments needing outpatient rehabilitation were not identified by the FSS score.

Postdischarge health resource use in pediatric survivors of prolonged mechanical ventilation for acute respiratory illness

We aimed to identify characteristics associated with postdischarge health resource use in children without medical complexity who survived an episode of prolonged mechanical ventilation for respiratory illness. We hypothesized that longer durations of mechanical ventilation, noncomplex chronic conditions, and severe acute respiratory distress syndrome (ARDS) would be associated with readmission or an Emergency Department (ED) visit. In this retrospective cohort, we evaluated children without a complex chronic condition who survived a respiratory illness requiring ≥3 days of mechanical ventilation and who had insurance eligibility within the Colorado All Payers Claims Database. We used insurance claims to characterize health resource use and multivariable logistic regression to identify characteristics associated with readmission or an ED visit during the postdischarge year. We evaluated 82 children, median age 12.8 months (interquartile range [IQR]: 4.0-24.1), 20 (24%) with a noncomplex chronic condition and 62 (76%) without any chronic conditions. Bronchiolitis (60%) and pneumonia/aspiration pneumonitis (17%) were the most common etiologies of respiratory failure and 47 (57%) patients had severe ARDS. Forty-six (56%) patients had an ED visit or readmission. Among the 18 readmitted patients, 16/18 (89%) readmissions were for respiratory illness. Forty (49%) patients had ≥2 outpatient pulmonary visits and 45 (55%) filled a pulmonary medication prescription. In analyses controlling for age, illness severity and mechanical ventilation duration, severe ARDS was predictive of ED visit or readmission (odds ratio [OR]: 5.53 [95% confidence interval [CI]: 1.79, 19.09]). Children who survive prolonged mechanical ventilation for respiratory disease experience high rates of postdischarge health resource use, particularly those surviving severe ARDS.

Identifying Long-Term Morbidities and Health Trajectories After Prolonged Mechanical Ventilation in Children Using State All Payer Claims Data

OBJECTIVES

To identify postdischarge outcome phenotypes and risk factors for poor outcomes using insurance claims data.

DESIGN

Retrospective cohort study.

SETTING

Single quaternary center.

PATIENTS

Children without preexisting tracheostomy who required greater than or equal to 3 days of invasive mechanical ventilation, survived the hospitalization, and had postdischarge insurance eligibility in Colorado's All Payer Claims Database.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We used unsupervised machine learning to identify functional outcome phenotypes based on claims data representative of postdischarge morbidities. We assessed health trajectory by comparing change in the number of insurance claims between quarters 1 and 4 of the postdischarge year. Regression analyses identified variables associated with unfavorable outcomes. The 381 subjects had median age 3.3 years (interquartile range, 0.9-12 yr), and 147 (39%) had a complex chronic condition. Primary diagnoses were respiratory (41%), injury (23%), and neurologic (11%). We identified three phenotypes: lower morbidity (n = 300), higher morbidity (n = 62), and 1-year nonsurvivors (n = 19). Complex chronic conditions most strongly predicted the nonsurvivor phenotype. Longer PICU stays and tracheostomy placement most strongly predicted the higher morbidity phenotype. Patients with high but improving postdischarge resource use were differentiated by high illness severity and long PICU stays. Patients with persistently high or increasing resource use were differentiated by complex chronic conditions and tracheostomy placement.

CONCLUSIONS

New morbidities are common after prolonged mechanical ventilation. Identifying phenotypes at high risk of postdischarge morbidity may facilitate prognostic enrichment in clinical trials.