title: Persistent problems 1 year after mild traumatic brain injury: a longitudinal population study in New Zealand.
abstract: BACKGROUND
  Mild traumatic brain injury (mTBI) is a common problem in general practice settings, yet previous research does not take into account those who do not attend hospital after injury. This is important as there is evidence that effects may be far from mild.
  
  
  OBJECTIVE
  To determine whether people sustain any persistent effects 1 year after mTBI, and to identify the predictors of health outcomes.
  
  
  METHODS
  A community-based, longitudinal population study of an mTBI incidence cohort (n = 341) from a mixed urban and rural region (Hamilton and Waikato Districts) of the North Island of New Zealand (NZ).
  
  
  METHODS
  Adults (>16 years) completed assessments of cognitive functioning, global functioning, post-concussion symptoms, mood, and quality of life over the year after injury.
  
  
  RESULTS
  Nearly half of participants (47.9%) reported experiencing four or more post-concussion symptoms 1 year post-injury. Additionally, 10.9% of participants revealed very low cognitive functioning. Levels of anxiety, depression, or reduced quality of life were comparable with the general population. Having at least one comorbidity, history of brain injury, living alone, non-white ethnic group, alcohol and medication use, and being female were significant predictors of poorer outcomes at 12 months.
  
  
  CONCLUSIONS
  Although some people make a spontaneous recovery after mTBI, nearly half continue to experience persistent symptoms linked to their injury. Monitoring of recovery from mTBI may be needed and interventions provided for those experiencing persistent difficulties. Demographic factors and medical history should be taken into account in treatment planning.
authors.affiliation: National Institute for Stroke and Applied Neuroscience;
authors.forename: Alice
authors.initials: A
authors.lastname: Theadom
authors.affiliation: National Institute for Health Innovation;
authors.forename: Varsha
authors.initials: V
authors.lastname: Parag
authors.affiliation: Primary Health Care and General Practice, University of Otago, Wellington, New Zealand.
authors.forename: Tony
authors.initials: T
authors.lastname: Dowell
authors.affiliation: Person Centred Research Centre, Health and Rehabilitation Institute; Auckland University of Technology, Auckland, New Zealand.
authors.forename: Kathryn
authors.initials: K
authors.lastname: McPherson
authors.affiliation: School of Psychology, University of Waikato, Hamilton, New Zealand.
authors.forename: Nicola
authors.initials: N
authors.lastname: Starkey
authors.affiliation: School of Psychology;
authors.forename: Suzanne
authors.initials: S
authors.lastname: Barker-Collo
authors.affiliation: National Institute for Stroke and Applied Neuroscience;
authors.forename: Kelly
authors.initials: K
authors.lastname: Jones
authors.affiliation: School of Population Health; University of Auckland, Auckland, New Zealand.
authors.forename: Shanthi
authors.initials: S
authors.lastname: Ameratunga
authors.affiliation: National Institute for Stroke and Applied Neuroscience;
authors.forename: Valery L
authors.initials: VL
authors.lastname: Feigin
mesh_terms: D000293:Adolescent; D000328:Adult; D001007:Anxiety / Q000453:epidemiology* / Q000209:etiology; D001924:Brain Concussion / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D003863:Depression / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D009520:New Zealand / Q000453:epidemiology; D011159:Population Surveillance; D011788:Quality of Life; D013997:Time Factors
keywords: epidemiology; head injury; mild traumatic brain injury; outcome; prediction