Patient presentations in outpatient settings: Epidemiology of adult head trauma treated outside of hospital emergency departments

Background: While deaths, hospitalizations, and emergency department visits for head trauma are well understood, little is known about presentations in outpatient settings. Our objective was to examine the epidemiology and extent of healthcare-seeking adult (18-64 years) head trauma patients presenting in outpatient settings compared with patients receiving nonhospitalized emergency department care. Methods: We used 2004-2013 MarketScan Medicaid/commercial claims to identify head trauma patients managed in outpatient settings (primary care provider, urgent care) and the emergency department. We examined differences in demographic and injury-specific factors, Centers for Disease Control and Prevention-defined head trauma diagnoses, and extent of and reasons for postindex visit ambulatory care use within 30/90/180 days by index visit location, as well as annual and monthly variations in head trauma trends. We used outpatient incidence rates to estimate the US nationwide outpatient burden. Results: A total of 1.19 million index outpatient visits were included (emergency department: 348,659). Nationwide, they represented a weighted annual burden of 1.16 million index outpatient cases. These encompassed 46% of all known healthcare-seeking head trauma in 2013 (outpatient/emergency department/inpatient/fatalities) and increased in magnitude (+31%) from 2004 to 2013. One fourth (27%) of office/clinic visits led to diagnosis with concussion on index presentation (urgent care: 32%). Distributions of demographic factors varied with index visit location while injury-specific factors were largely comparable. Subsequent visits reflected high demand for follow-up treatment, increased concussive diagnoses, and sequelae-associated care. Conclusions: Adult outpatient presentations of head trauma remain poorly understood. The results of this study demonstrate the extensive magnitude of their occurrence and close association with need for follow-up care.