Cases (with a history of TBI): 
1. Ages 50-95 years 
2. History of traumatic brain injury of sufficient severity to have resulted in medical attention (ascertained via the Ohio State University TBI Identification Questionnaire—OSU TBI-ID, and based on DoD/VA criteria) 
3. Residence in AFRH-Washington D.C. or the Veterans Home of California-Yountville 
4. MMSE score ≥ 20 
5. Capacity to provide consent to participate in research (assessment made by study physician) 
6. Ability to read and write English 
Controls (without a history of TBI): 
1. Ages 50-95 years 
2. No history of traumatic brain injury of sufficient severity to have resulted in medical attention (ascertained via the Ohio State University TBI Identification Questionnaire—OSU TBI-ID) 
3. Residence in AFRH-Washington or the Veterans Home of California-Yountville 
4. MMSE score ≥ 20 
5. Capacity to provide consent or assent to participate in research 
6. Ability to read and write English - 

NCT01891383_inc_T2
Person
Ages
NCT01891383_inc_T3
Value
50-95 years
NCT01891383_inc_T4
Condition
traumatic brain injury
NCT01891383_inc_T5
Observation
History
NCT01891383_inc_T6
Qualifier
sufficient severity
NCT01891383_inc_T8
Measurement
Ohio State University TBI Identification Questionnaire—OSU TBI-ID
NCT01891383_inc_T9
Value
sufficient severity
NCT01891383_inc_T10
Visit
AFRH-Washington D.C.
NCT01891383_inc_T11
Visit
Veterans Home of California-Yountville
NCT01891383_inc_T12
Measurement
MMSE
NCT01891383_inc_T13
Value
score ≥ 20
NCT01891383_inc_T19
Person
Ages
NCT01891383_inc_T20
Value
50-95 years
NCT01891383_inc_T21
Condition
traumatic brain injury
NCT01891383_inc_T22
Qualifier
sufficient severity
NCT01891383_inc_T23
Measurement
Ohio State University TBI Identification Questionnaire—OSU TBI-ID
NCT01891383_inc_T24
Negation
No
NCT01891383_inc_T25
Observation
history
NCT01891383_inc_T27
Value
sufficient severity
NCT01891383_inc_T28
Visit
AFRH-Washington
NCT01891383_inc_T29
Visit
Veterans Home of California-Yountville
NCT01891383_inc_T30
Observation
Residence
NCT01891383_inc_T31
Observation
Residence
NCT01891383_inc_T32
Scope
AFRH-Washington D.C. or the Veterans Home of California-Yountville
NCT01891383_inc_T33
Scope
AFRH-Washington or the Veterans Home of California-Yountville
NCT01891383_inc_T34
Measurement
MMSE
NCT01891383_inc_T35
Value
score ≥ 20