Population based study on patients with traumatic brain injury suggests increased risk of dementia

Wang, Hao‐Kuang; Lin, Sheng Hsiang; Sung, Pi Shan; Wu, Ming Hsiu; Hung, Kuo Wei; Wang, Liang Chao; Huang, Chih Yuan; Lu, Kang; Chen, Han Jung; Tsai, Kuen‐Jer

doi:10.1136/jnnp-2012-302633

Cited by 150 publications

(125 citation statements)

References 41 publications

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“…Stratified analyses found the highest adjusted risk for dementia related to TBI (HR [95% CI]: 3.87 [1.98-7.57]) in the youngest (15-29 years) age group which may reflect enduring cognitive sequelae of severe TBI given the short duration of follow-up, followed by the oldest (75+ years) age group (95% CI): 2.60 (2.33-2.91) in which reverse causation may partially explain findings. The authors noted that AD was not the most common subtype of dementia diagnosed in cases with a history of TBI [40]. Moreover, in each of these four studies that compared individuals with and without TBI, individuals with TBI had significantly higher rates of co-morbid medical conditions at baseline [37][38][39][40].…”

Section: • • Studies Reporting a Clear Relationship Between Tbi And Demmentioning

confidence: 99%

“…The authors noted that AD was not the most common subtype of dementia diagnosed in cases with a history of TBI [40]. Moreover, in each of these four studies that compared individuals with and without TBI, individuals with TBI had significantly higher rates of co-morbid medical conditions at baseline [37][38][39][40].…”

Section: • • Studies Reporting a Clear Relationship Between Tbi And Demmentioning

confidence: 99%

“…After stratifying by age and TBI severity, the authors reported that moderate-severe TBI was associated with increased dementia risk across all age groups, though mTBI was only associated with increased dementia risk above aged 65 years. Two additional retrospective cohort studies [39,40] that found a positive relationship between TBI and dementia used the same national health insurance database but approached the analyses somewhat differently.…”

Section: • • Studies Reporting a Clear Relationship Between Tbi And Demmentioning

confidence: 99%

“…However, the average time between mTBI and dementia diagnosis PersPective Dams-O'Connor, Guetta, Hahn-Ketter & Fedor future science group was 1 year, suggesting reverse causation may at least partially explain results. The other study using this national health claims database [40] identified individuals who received care for a TBI of any severity over a 5-year period, identified matched comparison cases by age, sex and year of index (non-TBI) ambulatory care visit and tracked both groups for 5 years to identify those who were subsequently diagnosed with dementia. After controlling for demographics and select co-morbidities, the adjusted HR (95% CI) for dementia associated with TBI was 1.68 (1.57-1.80).…”

Section: • • Studies Reporting a Clear Relationship Between Tbi And Demmentioning

confidence: 99%

See 3 more Smart Citations

Traumatic Brain Injury As a Risk Factor for Alzheimer’s Disease: Current Knowledge and Future Directions

Dams-O’Connor

Guetta

Hahn-Ketter

et al. 2016

Neurodegener. Dis. Manag.

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There is growing concern about the late effects of traumatic brain injury (TBI). This scoping review summarizes clinical research from the past 10 years that evaluates the relationship between TBI and Alzheimer's disease. This review identified five studies that found increased risk for dementia after TBI, two studies that found no increased risk and four studies that found a relationship only under certain conditions or in specified subsamples. Methodological differences across studies preclude direct comparison of results, and discrepant findings elucidate the complex course of post-TBI neurodegeneration. We discuss the factors that influence the strength and direction of the relationship between TBI and Alzheimer's disease, and the implications of this body of research for patient care and future research.

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Section: • • Studies Reporting a Clear Relationship Between Tbi And Demmentioning

confidence: 99%

Section: • • Studies Reporting a Clear Relationship Between Tbi And Demmentioning

confidence: 99%

Section: • • Studies Reporting a Clear Relationship Between Tbi And Demmentioning

confidence: 99%

Section: • • Studies Reporting a Clear Relationship Between Tbi And Demmentioning

confidence: 99%

See 2 more Smart Citations

Traumatic Brain Injury As a Risk Factor for Alzheimer’s Disease: Current Knowledge and Future Directions

Dams-O’Connor

Guetta

Hahn-Ketter

et al. 2016

Neurodegener. Dis. Manag.

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“…1 However, prior research on the relationship between TBI and risk of Alzheimer disease (AD) and all-cause dementia has been mixed. [2][3][4][5][6][7][8][9][10][11][12][13][14] Most prior studies have not adequately controlled for potential confounders, such as medical and psychiatric comorbidities, and none have considered death as a competing risk.…”

mentioning

confidence: 99%

Traumatic brain injury and risk of dementia in older veterans

et al. 2014

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Objectives: Traumatic brain injury (TBI) is common in military personnel, and there is growing concern about the long-term effects of TBI on the brain; however, few studies have examined the association between TBI and risk of dementia in veterans.Methods: We performed a retrospective cohort study of 188,764 US veterans aged 55 years or older who had at least one inpatient or outpatient visit during both the baseline (2000)(2001)(2002)(2003) and follow-up (2003-2012) periods and did not have a dementia diagnosis at baseline. TBI and dementia diagnoses were determined using ICD-9 codes in electronic medical records. Fine-Gray proportional hazards models were used to determine whether TBI was associated with greater risk of incident dementia, accounting for the competing risk of death and adjusting for demographics, medical comorbidities, and psychiatric disorders.Results: Veterans were a mean age of 68 years at baseline. During the 9-year follow-up period, 16% of those with TBI developed dementia compared with 10% of those without TBI (adjusted hazard ratio, 1.57; 95% confidence interval: 1.35-1.83). There was evidence of an additive association between TBI and other conditions on risk of dementia.Conclusions: TBI in older veterans was associated with a 60% increase in the risk of developing dementia over 9 years after accounting for competing risks and potential confounders. Our results suggest that TBI in older veterans may predispose toward development of symptomatic dementia and raise concern about the potential long-term consequences of TBI in younger veterans and civilians. There is growing evidence that traumatic brain injury (TBI) is associated with a variety of shortand long-term adverse health outcomes. A 2008 Institute of Medicine report concluded that TBIs are consistently associated with an increased risk of unprovoked seizures, premature mortality, and neurocognitive deficits in the affected region, with evidence strongest for penetrating wounds and severe or moderate TBIs.1 However, prior research on the relationship between TBI and risk of Alzheimer disease (AD) and all-cause dementia has been mixed. [2][3][4][5][6][7][8][9][10][11][12][13][14] Most prior studies have not adequately controlled for potential confounders, such as medical and psychiatric comorbidities, and none have considered death as a competing risk.Furthermore, to our knowledge, only one prior study has specifically focused on examining the relationship between TBI and risk of dementia in veterans.11 Many veterans have other combatrelated risk factors such as posttraumatic stress disorder (PTSD) and depression, which have been associated with an increased risk of dementia in veterans in prior studies, 15,16 and could act as either confounders or effect modifiers of the association between TBI and dementia in veterans.

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Association of Mild Traumatic Brain Injury With and Without Loss of Consciousness With Dementia in US Military Veterans

et al. 2018

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IMPORTANCE Traumatic brain injury (TBI) is common in both veteran and civilian populations. Prior studies have linked moderate and severe TBI with increased dementia risk, but the association between dementia and mild TBI, particularly mild TBI without loss of consciousness (LOC), remains unclear. OBJECTIVE To examine the association between TBI severity, LOC, and dementia diagnosis in veterans. DESIGN, SETTING, AND PARTICIPANTS This cohort study of all patients diagnosed with a TBI in the Veterans Health Administration health care system from October 1, 2001, to September 30, 2014, and a propensity-matched comparison group. Patients with dementia at baseline were excluded. Researchers identified TBIs through the Comprehensive TBI Evaluation database, which is restricted to Iraq and Afghanistan veterans, and the National Patient Care Database, which includes veterans of all eras. The severity of each TBI was based on the most severe injury recorded and classified as mild without LOC, mild with LOC, mild with LOC status unknown, or moderate or severe using Department of Defense or Defense and Veterans Brain Injury Center criteria. International Classification of Diseases, Ninth Revision codes were used to identify dementia diagnoses during follow-up and medical and psychiatric comorbidities in the 2 years prior to the index date. MAIN OUTCOMES AND MEASURES Dementia diagnosis in veterans who had experienced TBI with or without LOC and control participants without TBI exposure. RESULTS The study included 178 779 patients diagnosed with a TBI in the Veterans Health Administration health care system and 178 779 patients in a propensity-matched comparison group. Veterans had a mean (SD) age of nearly 49.5 (18.2) years at baseline; 33 250 (9.3%) were women, and 259 136 (72.5%) were non-Hispanic white individuals. Differences between veterans with and without TBI were small. A total of 4698 veterans (2.6%) without TBI developed dementia compared with 10 835 (6.1%) of those with TBI. After adjustment for demographics and medical and psychiatric comobidities, adjusted hazard ratios for dementia were 2.36 (95% CI, 2.10-2.66) for mild TBI without LOC, 2.51 (95% CI, 2.29-2.76) for mild TBI with LOC, 3.19 (95% CI, 3.05-3.33) for mild TBI with LOC status unknown, and 3.77 (95% CI, 3.63-3.91) for moderate to severe TBI. CONCLUSIONS AND RELEVANCE In this cohort study of more than 350 000 veterans, even mild TBI without LOC was associated with more than a 2-fold increase in the risk of dementia diagnosis. Studies of strategies to determine mechanisms, prevention, and treatment of TBI-related dementia in veterans are urgently needed.

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Population based study on patients with traumatic brain injury suggests increased risk of dementia

Abstract: The findings of this study suggest an increased risk of dementia among individuals with TBI. We suggest the need for more intensive medical monitoring and health education in individuals with TBI.

Cited by 150 publications

References 41 publications

Traumatic Brain Injury As a Risk Factor for Alzheimer’s Disease: Current Knowledge and Future Directions

Traumatic Brain Injury As a Risk Factor for Alzheimer’s Disease: Current Knowledge and Future Directions

Traumatic brain injury and risk of dementia in older veterans

Association of Mild Traumatic Brain Injury With and Without Loss of Consciousness With Dementia in US Military Veterans

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