title: Epidemiology of spinal cord injury without radiographic abnormality in children: a nationwide perspective.
abstract: OBJECTIVE
  To characterize the epidemiology and costs associated with spinal cord injury without radiographic abnormality (SCIWORA) based on patient age.
  
  
  METHODS
  An analysis of data complied for 2012 in the Healthcare Utilization Project KID database (HCUP-KID), which represents a nationwide database of pediatric admissions, was performed. An initial search identified all children diagnosed with SCIWORA based on International Classification of Diseases, 9th edition (ICD-9) codes. Only data on patients aged <18 years were included in the analysis. The associated codes were then searched to identify the cause of injury. Pertinent epidemiologic data were collected from the database, including age, gender, and racial group. Injury level and pattern were determined from the associated ICD-9 codes, as were associated injuries. Hospital data included length of stay, in-hospital mortality, total hospital charges, and primary payer. All data were compiled and stratified based on patient age into three groups: group 1, age 0-3 years; group 2, age 4-10 years; group 3, age 11-17 years. These data were compared using Student's t test and Chi-squared analyses.
  
  
  RESULTS
  A total of 297 patients were identified who met the inclusion criteria. There was a slight predominance of females among the youngest patients (53 %) with a significant dominance of males in the oldest group (72 %) (p < 0.001). The most common race among the patients studied was white (50 %) followed by Hispanic (14 %), Black (12 %), Asian/Pacific Islander (4 %), and Native American (1 %). Overall, the most common cause of injury was sports injuries, which were responsible for 122/297 (41 %) injuries, followed by motor vehicle collisions (26 %). Mechanisms of injury were significantly varied based on age group, with motor vehicle collisions the most common cause in the youngest two age groups and sports injuries the most common in the oldest age group (p < 0.05). The most common location injured was the cervical spine (46 %), with the upper cervical spine most commonly injured, particularly in the younger age groups. Additional injuries were found in 158/297 (53 %) of patients, and these were more common among younger patients. Head trauma was the most common associated injury in all age groups, but the highest rate was found the youngest age groups (p < 0.0001). The average hospital stay for all patients was 13 days, with longer stays seen in younger age groups (p < 0.05). In-hospital mortality was uncommon among these patients and occurred in only 6/297 (2 %) of patients. Hospital charges were highest in the younger age groups, with an average charge of $210,772 for those in the youngest age group, decreasing to $72,178 for those in group 3 (p < 0.0005). The most common payer was public insurance/medicaid in the youngest age group and private insurance in groups 2 and 3 (p < 0.0001).
  
  
  CONCLUSIONS
  SCIWORA is an uncommon but potentially devastating injury in children. As with many pediatric injuries, this injury is heterogeneous between children of differing ages. This analysis of a nationwide series of children with such injuries identified significant differences in injury location, causes of injury, associated injuries, and hospital charges associated with this diagnosis.
authors.affiliation: Tripler Army Medical Center Orthopedic Surgery Service (MCHK-DSO), 1 Jarrett White Road, Honolulu, HI, 96859, USA. jeffrey.b.knox.mil@mail.mil.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Knox
keywords: Epidemiology; Sciwora; Spinal cord injury; Trauma