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Dementia risk after traumatic brain injury vs nonbrain trauma: the role of age and severity
Gardner RC, Burke JF, Nettiksimmons J, Kaup A, Barnes DE, Yaffe K.. JAMA neurology, 2014-12-01
Topic: Risk, prevention and care in population studies
Importance Epidemiologic evidence regarding the importance of traumatic brain injury (TBI) as a risk factor for dementia is conflicting. Few previous studies have used patients with non-TBI trauma (NTT) as controls to investigate the influence of age and TBI severity. Objective To quantify the risk of dementia among adults with recent TBI compared with adults with NTT. Design, setting, and participants This retrospective cohort study was performed from January 1, 2005, through December 31, 2011 (follow-up, 5-7 years). All patients 55 years or older diagnosed as having TBI or NTT in 2005 and 2006 and who did not have baseline dementia or die during hospitalization (n = 164,661) were identified in a California statewide administrative health database of emergency department (ED) and inpatient visits. Exposures Mild vs moderate to severe TBI diagnosed by Centers for Disease Control and Prevention criteria using International Classification of Diseases, Ninth Revision (ICD-9)codes, and NTT, defined as fractures excluding fractures of the head and neck, diagnosed using ICD-9 codes. Main outcomes and measures Incident ED or inpatient diagnosis of dementia (using ICD-9 codes) 1 year or more after initial TBI or NTT. The association between TBI and risk of dementia was estimated using Cox proportional hazards models before and after adjusting for common dementia predictors and potential confounders. We also stratified by TBI severity and age category (55-64, 65-74, 75-84, and ≥85 years). Results A total of 51,799 patients with trauma (31.5%) had TBI. Of these, 4361 (8.4%) developed dementia compared with 6610 patients with NTT (5.9%) (P Conclusions and relevance Among patients evaluated in the ED or inpatient settings, those with moderate to severe TBI at 55 years or older or mild TBI at 65 years or older had an increased risk of developing dementia. Younger adults may be more resilient to the effects of recent mild TBI than older adults.
Key findings
- Objective To quantify the risk of dementia among adults with recent TBI compared with adults with NTT.
- Results A total of 51,799 patients with trauma (31.5%) had TBI.
- Of these, 4361 (8.4%) developed dementia compared with 6610 patients with NTT (5.9%) (P < .001).
Why it matters
This cohort study found that adults aged 55 and older with moderate to severe traumatic brain injury, or those 65 and older with mild traumatic brain injury, had an increased risk of developing dementia compared with people who had non-brain trauma. It is about risk after injury, not about treating or preventing Alzheimer's disease.
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Study details
- Study designcohort study
- Participants164,661
- Effect size31.5%; 8.4%; 5.9%
- Evidence strengthModerate
How this study scored 72/100
Published in a leading specialty journal, and it is a cohort study following people over time. Scored zero for randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (JAMA neurology) |
| Journal's citation record | 2 / 4 | JAMA Neurology: journal h-index 235 (OpenAlex, 2026-10-29) |
| Study design | 7 / 12 | A cohort study following people over time |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2014 — within 20 year(s) of the newest study here |
| Sample size | 4 / 4 | 164,661 participants |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 6 / 7 | Cited 450 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 32.1 citations a year over 14 year(s) since 2014 |
| Impact for its field and year | 5 / 6 | Cited 22.8× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 14 other studies in this library |
| Still being cited | 3 / 4 | Cited 97 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Kristine S. Yaffe: h-index 155 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University of Michigan: institution h-index 2,240 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 7 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 25347255) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 72 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.1001/jamaneurol.2014.2668
- PubMed: 25347255
- Original source →
- Free full text: PubMed Central →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Gardner, R. C., Burke, J. F., Nettiksimmons, J., Kaup, A., Barnes, D. E., & Yaffe, K. (2014). Dementia risk after traumatic brain injury vs nonbrain trauma: the role of age and severity. JAMA neurology. https://doi.org/10.1001/jamaneurol.2014.2668
Vancouver
Gardner RC, Burke JF, Nettiksimmons J, Kaup A, Barnes DE, Yaffe K. Dementia risk after traumatic brain injury vs nonbrain trauma: the role of age and severity. JAMA neurology. 2014. doi:10.1001/jamaneurol.2014.2668. PMID: 25347255.
BibTeX
@article{gardner2014-25347255,
author = {Gardner, R. C. and Burke, J. F. and Nettiksimmons, J. and Kaup, A. and Barnes, D. E. and Yaffe, K.},
title = {{Dementia risk after traumatic brain injury vs nonbrain trauma: the role of age and severity}},
journal = {JAMA neurology},
year = {2014},
doi = {10.1001/jamaneurol.2014.2668},
pmid = {25347255},
url = {https://doi.org/10.1001/jamaneurol.2014.2668}
}
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