The International Incidence of Traumatic Brain Injury: A Systematic Review and Meta-Analysis.
BACKGROUND
Understanding the epidemiology of traumatic brain injury (TBI) is essential to shape public health policy, implement prevention strategies, and justify allocation of resources toward research, education, and rehabilitation in TBI. There is not, to our knowledge, a systematic review of population-based studies addressing the epidemiology of TBI that includes all subtypes. We performed a comprehensive systematic review and meta-analysis of the worldwide incidence of TBI.


METHODS
A search was conducted on May 23, 2014, in Medline and EMBASE according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Abstracts were screened independently and in duplicate to identify original research. Study quality and ascertainment bias were assessed in duplicate using a previously published tool. Demographic data and incidence estimates from each study were recorded, along with stratification by age, gender, year of data collection, and severity.


RESULTS
The search strategy yielded 4944 citations. Two hundred and sixteen articles met criteria for full-text review; 144 were excluded. Hand searching resulted in ten additional articles. Eighty-two studies met all eligibility criteria. The pooled annual incidence proportion for all ages was 295 per 100,000 (95% confidence interval: 274-317). The pooled incidence rate for all ages was 349 (95% confidence interval: 96.2-1266) per 100,000 person-years. Incidence proportion and incidence rate were examined to see if associated with age, sex, country, or severity.


CONCLUSIONS
We conclude that most TBIs are mild and most TBIs occur in males among the adult population. The incidence of TBI varies widely by ages and between countries. Despite being an important medical, economic, and social problem, the global epidemiology of TBI is still not well-characterized in the current literature. Understanding the incidence of TBI, particularly mild TBI, remains challenging because of nonstandardized reporting among neuroepidemiological studies.
1Department of Clinical Neurosciences,University of Calgary,Calgary,Alberta,Canada.
Rita
R
Nguyen
1Department of Clinical Neurosciences,University of Calgary,Calgary,Alberta,Canada.
Kirsten M
KM
Fiest
2Department of Community Health Sciences & O'Brien Institute for Public Health,University of Calgary,Calgary,Alberta,Canada.
Jane
J
McChesney
4Department of Neurosurgery,King's College Hospital,Denmark Hill,London,UK.
Churl-Su
CS
Kwon
1Department of Clinical Neurosciences,University of Calgary,Calgary,Alberta,Canada.
Nathalie
N
Jette
2Department of Community Health Sciences & O'Brien Institute for Public Health,University of Calgary,Calgary,Alberta,Canada.
Alexandra D
AD
Frolkis
1Department of Clinical Neurosciences,University of Calgary,Calgary,Alberta,Canada.
Callie
C
Atta
1Department of Clinical Neurosciences,University of Calgary,Calgary,Alberta,Canada.
Sarah
S
Mah
1Department of Clinical Neurosciences,University of Calgary,Calgary,Alberta,Canada.
Harinder
H
Dhaliwal
5Department of Neurology,University of California Los Angeles,Los Angeles,California.
Aylin
A
Reid
1Department of Clinical Neurosciences,University of Calgary,Calgary,Alberta,Canada.
Tamara
T
Pringsheim
2Department of Community Health Sciences & O'Brien Institute for Public Health,University of Calgary,Calgary,Alberta,Canada.
Jonathan
J
Dykeman
1Department of Clinical Neurosciences,University of Calgary,Calgary,Alberta,Canada.
Clare
C
Gallagher
D000367:Age Factors; D000070642:Brain Injuries, Traumatic / Q000453:epidemiology*; D016206:Databases, Bibliographic / Q000706:statistics & numerical data; D014943:Global Health; D006801:Humans; D015994:Incidence; D012737:Sex Factors
Epidemiology; Head Trauma; Incidence; Systematic Review; Traumatic Brain Injury