Eric Coon, MD, MSCI Assistant Professor of Pediatrics Division of Inpatient Medicine University of Utah Trends of head CT imaging, detection of intracranial bleeding and skull fractures, and outcomes in pediatric head injury

Eric Coon has documented no financial relationships to disclose or Conflicts of Interest (COIs) to resolve.

Acknowledgements Alan Schroeder, MD Hospital Medicine and Critical Care, Stanford University Susan Bratton, MD, MPH Critical Care, University of Utah Matt Hall, PhD Statistician, Children’s Hospital Association Tom Newman, MD, MPH Epidemiology & Biostatistics and Pediatrics, UCSF Jacob Wilkes Data Analyst, Intermountain

Background Childhood head trauma is common Prediction rules 1 & national campaigns 2 reduction in head CT use CT exposure Malignancy 3 Overdiagnosis 1 Kuppermann et al. Lancet Oct Pearce et al. Lancet Aug.

Weiner et al. BMJ Jul. Disease Incidence and Outcomes

Aim Compare trends in head CT imaging to trends in the detection of intracranial abnormalities and patient outcomes among a cohort of children with isolated head injury

Methods Retrospective cohort Children presenting for isolated head trauma to PHIS hospitals ED, Observation, Inpatient Between Jan 2001-Dec 2014

Inclusion Criteria Patients ≤18 yo with any of the following ICD-9 discharge diagnosis codes: Skull Fracture, Concussion, 850 Intracranial bleed, Head injury unspecified,

Exclusions Neurologic diagnosis prior to index head trauma visit Non-accidental trauma code during index head trauma visit Directly admitted to PHIS hospital Transferred out of PHIS hospital Hospitals with annual changes in the proportion of ED, inpatient, or observation visit types that exceed Tukey’s outlier rule* Procedure or imaging of body part besides head on initial presentation Diagnosis code for injury of any body part besides the head *Tukey’s outlier rule:Y (Q IQR)

Cohort characteristics, N=263,591

Skull X-ray -0.30% per year* (-0.32% to -0.27%) Imaging Trends Head CT -1.54% per year* (-1.60% to -1.48%) MRI 0.03% per year* (0.02% to 0.04%) Any Head Imaging -1.73% per year* (-1.79% to -1.67%) *p <0.05

Abnormality Trends Skull Fractures -0.17% per year* (-0.20% to -0.14%) Intracranial Bleeds -0.12% per year* (-0.14% to -0.10%) *p <0.05

Hospitalization -0.25% per year* (-0.28% to -0.22%) Mortality % per year ( % to %) Outcome Trends Neurosurgery -0.03% per year* (-0.04% to -0.02%) Re-Visit -0.01% per year (-0.02% to 0.01%) *p <0.05

Head CT Skull X-ray MRI Any Head Imaging Skull Fractures Intracranial Bleeds Re-Visits Mortality Hospitalization Neurosurgery +0.1%-1.0%-2.0%0 Summary

For every 10,000 head imaging studies avoided … 149 fewer fractures detected 49 fewer bleeds detected 24 fewer hospitalizations 1 fewer neurosurgery performed No apparent change in re-visit or mortality

Variation in Head CT Testing Among Children’s Hospitals

Limitations Relying on administrative data Changing nature of isolated head trauma Lack imaging details Outcome ascertainment bias Mortality is rare

Implications Some intracranial abnormalities may be overdiagnosed Benefit of avoiding unnecessary head imaging in isolated head trauma extends beyond immediate costs and risks associated with radiation Continued variation implies opportunities for more judicious head imaging remain

Patients and PHIS sites, by year