Characterizing Hospitalizations for Pediatric Concussion and Trends in Care

Approximately 14% of children who sustain a concussion are admitted to the hospital,¹ although admission rates reportedly vary substantially among pediatric hospitals.² Children hospitalized for concussion may be at a higher risk for persistent postconcussive symptoms,^3,4 yet little is known about this subset of children and how they are managed while in the hospital. Characterizing children hospitalized for concussion and describing the inpatient care they received will promote hypothesis generation for further inquiry into indications for admission, as well as the relationship between inpatient management and concussion recovery.

We described a cohort of children admitted to 40 pediatric hospitals primarily for concussion and detailed care delivered during hospitalization. We explored individual-level factors and their association with prolonged length of stay (LOS) and emergency department (ED) readmission. Finally, we evaluated if there had been changes in inpatient care over the 8-year study period.

Study Design

The Institutional Review Board determined that this retrospective cohort study was exempt from review.

Data Source

The Children’s Hospital Association’s Pediatric Health Information System (PHIS) is an administrative database from pediatric hospitals located within 17 major metropolitan areas in the United States. Data include: service dates, patient demographics, payer type, diagnosis codes, resource utilization information (eg, medications), and hospital characteristics.^1,5 De-identified data undergo reliability and validity checks prior to inclusion.^1,5 We analyzed data from 40 of 43 hospitals that contributed inpatient data during our study period. 2 hospitals were excluded due to inconsistent data submission, and 1 removed their data.

Study Population

Data were extracted for children 0 to 17 years old who were admitted to an inpatient or observational unit between January 1, 2007 and December 31, 2014 for traumatic brain injury (TBI). Children were identified using International Classification of Diseases, Clinical Modification, Ninth Revision (ICD-9-CM) diagnosis codes that denote TBI per the Centers for Disease Control (CDC): 800.0–801.9, 803.0–804.9, 850–854.1, and 959.01.^6–8 To examine inpatient care for concussion, we only retained children with a primary (ie, first) concussion-related diagnosis code (850.0–850.9⁹) for analyses. For patients with multiple visits during our study period, only the index admission was analyzed. We refined our cohort using 2 injury scores calculated from ICD-9-CM diagnosis codes using validated ICDMAP-90 injury coding software.^6,10–12 The Abbreviated Injury Scale (AIS) ranges from 1 (minor injury) to 6 (not survivable). The total Injury Severity Score (ISS) is based on 6 body regions (head/neck, face, chest, abdomen, extremity, and external) and calculated by summing the squares of the 3 worst AIS scores.¹³ A concussion receives a head AIS score of 2 if there is an associated loss of consciousness or a score of 1 if there is not; therefore, children were excluded if the head AIS score was >2. We also excluded children with the following features, as they may be indicative of more severe injuries that were likely the cause of admission: ISS > 6, secondary diagnosis code of skull fracture or intracranial injury, intensive care unit (ICU) or operating room (OR) charges, or a LOS > 7 days. Because some children are hospitalized for potentially abusive minor head trauma pending a safe discharge plan, we excluded children 0 to 4 years of age with child abuse, which was determined using a specific set of diagnosis codes (E960-E96820, 995.54, and 995.55) similar to previous research.¹⁴

Data Elements and Outcomes

Outcomes

Based on previous reports,^1,15 a LOS ≥ 2 days distinguished a typical hospitalization from a prolonged one. ED revisit was identified when a child had a visit with a TBI-related primary diagnosis code at a PHIS hospital within 30 days of initial admission and was discharged home. We limited analyses to children discharged, as children readmitted may have had an initially missed intracranial injury.

Patient Characteristics

We examined the following patient variables: age, race, sex, presence of chronic medical condition, payer type, household income, area of residence (eg, rural versus urban), and mechanism of injury. Age was categorized to represent early childhood (0 to 4 years), school age (5 to 12 years), and adolescence (12 to 17 years). Race was grouped as white, black, or other (Asian, Pacific Islander, American Indian, and “other” per PHIS). Ethnicity was described as Hispanic/Latino or not Hispanic/Latino. Children with medical conditions lasting at least 12 months and comorbidities that may impact TBI recovery were identified using a subgrouping of ICD-9-CM codes for children with “complex chronic conditions”.¹⁶ Payer type was categorized as government, private, and self-pay. We extracted a PHIS variable representing the 2010 median household income for the child’s home zip code and categorized it into quartiles based on the Federal Poverty Level for a family of 4.^17,18 Area of residence was defined using a Rural–Urban Commuting Area (RUCA) classification system¹⁹ and grouped into large urban core, suburban area, large rural town, or small rural town/isolated rural area.¹⁷ Mechanism of injury was determined using E-codes and categorized using the CDC injury framework,²⁰ with sports-related injuries identified using a previously described set of E-codes.¹ Mechanisms of injury included fall, motor vehicle collision, other motorized transport (eg, all-terrain vehicles), sports-related, struck by or against (ie, objects), and all others (eg, cyclists).