title: Frailty and injury causation.
abstract: OBJECTIVE
  : The current study will attempt to elucidate whether frailty has a role in motor vehicle crash injury causation.
  
  
  METHODS
  : The association between frailty and injury was studied among Crash Injury Research Engineering Network (CIREN) cases. The baseline "physical functioning" (PF) score of the SF-36 was used as a marker of frailty (i.e., PF score <75). Frailty associations with ISS and occupant, vehicular and crash factors were explored. Frailty association with delta V was analyzed among injured (i.e., brain, rib, or femur) belted occupants in frontal crashes to establish whether frailty confers a different risk of each particular injury.
  
  
  RESULTS
  : Frailty occurred in 13.7 % of the cohort (n=1,747). Median (q1-q3) ISS was 14.0 (10-22) among the frail and 17.0 (10-24) among the non frail (p=0.40). Frailty was significantly associated with advanced age, male gender, the presence of co-morbidities, extreme BMIs, frontal and near-side crashes and delta V < 45 km/h. Seat belt use and ISS<16 were not associated with frailty. Multiple linear regressions, adjusting for age, gender and BMI revealed a negative association between frailty and log delta V (coefficient -0.188, p=0.04) among those with rib fractures but not among those with brain injuries or femur fractures.
  
  
  CONCLUSIONS
  : PF score, a marker of frailty, is associated with similar ISS and lower delta V and is independently linked to lower delta V thresholds for some injuries (i.e. rib fractures) but not for others (i.e. brain injuries and femur fractures). These associations suggest a potential role of frailty in injury causation.
authors.affiliation: The Charles C. Mathias, Jr. National Study Center for Trauma and EMS, University of Maryland, Baltimore, MD (GER, PCD, CAB, TJK, JK); Program in Trauma, University of Maryland, Baltimore, MD (GER); Center for Medicare and Medicaid Services, US Department of Health and Human Services (DA).
authors.forename: Gabriel E
authors.initials: GE
authors.lastname: Ryb
authors.forename: Patricia C
authors.initials: PC
authors.lastname: Dischinger
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Burch
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Kerns
authors.forename: Joseph
authors.initials: J
authors.lastname: Kufera
authors.forename: Daniel
authors.initials: D
authors.lastname: Andersen
mesh_terms: D000063:Accidents, Traffic; D001930:Brain Injuries; D006801:Humans; D012253:Rib Fractures; D012622:Seat Belts