title: Previous head injury is a risk factor for subsequent head injury in children: a longitudinal cohort study.
abstract: OBJECTIVE
  The objective of this study was to determine whether children who sought care for a head injury were at greater risk of having a subsequent head injury within the following 6 and 12 months compared with children who sought care for an injury other than to the head.
  
  
  METHODS
  This was a longitudinal cohort study conducted in the emergency departments of 2 Montreal (Quebec, Canada) pediatric hospitals.
  
  
  METHODS
  The parents of 11,867 injured children aged 1 to 18 years were interviewed by telephone at 6 (n = 10,315) and 12 (n = 9486) months after their child's injury to ascertain outcome (ie, subsequent head injury) and to provide information on potential risk factors (age, gender, chronic medical condition, activity level, and socioeconomic status).
  
  
  METHODS
  The outcome of interest was a head injury requiring medical attention within the following year ascertained by parental recall or physician claims data.
  
  
  RESULTS
  A total of 245 and 386 previously head-injured children sustained a subsequent head injury within 6 and 12 months, respectively. Children who sought care for an initial head injury (n = 3599) were at higher risk of having a subsequent head injury within 6 months than children who sought care for an injury not to the head (n = 6716). The adjusted odds ratio suggested weak confounding by age, gender, and history of previous head injury. Results were consistent on the basis of physician claims data and 12-month follow-up interview data.
  
  
  CONCLUSIONS
  These results provide evidence that having a head injury increases a child's risk of having a subsequent head injury. Although age, gender, and history of previous head injury confound the relationship, the effect remains substantial.
authors.affiliation: School of Rehabilitation, Université de Montréal, Montréal, Québec, Canada. bonnie.swaine@umontreal.ca
authors.forename: Bonnie R
authors.initials: BR
authors.lastname: Swaine
authors.forename: Camille
authors.initials: C
authors.lastname: Tremblay
authors.forename: Robert W
authors.initials: RW
authors.lastname: Platt
authors.forename: Guy
authors.initials: G
authors.lastname: Grimard
authors.forename: Xun
authors.initials: X
authors.lastname: Zhang
authors.forename: I Barry
authors.initials: IB
authors.lastname: Pless
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003131:Combined Modality Therapy; D006259:Craniocerebral Trauma / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D004636:Emergency Service, Hospital; D005260:Female; D006776:Hospitals, Pediatric; D006801:Humans; D015994:Incidence; D007223:Infant; D015601:Injury Severity Score; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D015999:Multivariate Analysis; D011336:Probability; D011379:Prognosis; D011792:Quebec / Q000453:epidemiology; D012008:Recurrence; D018570:Risk Assessment; D017678:Sex Distribution