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Table 2 Inclusion and exclusion criteria

From: Developing methods to detect and diagnose chronic traumatic encephalopathy during life: rationale, design, and methodology for the DIAGNOSE CTE Research Project


Inclusion criteria

Exclusion criteria

All participants

(N = 240)

Male; age 45–74; no contraindications for MRI, LP, or PET procedures; English as primary language; agree to all procedures; willingness to have and availability of a study partner (i.e., informant who knows the participant well, speaks or visits with participant at least weekly for a minimum of 6 months, is > 18 years of age, has English as primary language) who agrees to participate in a telephone interview and respond to a series of online questionnaires.

History of clinical stroke or significant neurologic condition; vision or hearing impairment severe enough to compromise neuropsychological testing; impaired decisional capacity to provide informed consent to participate in study; currently clinically significant infectious disease, endocrine or metabolic disease, pulmonary, kidney or liver impairment, or cancer; body weight > 400 pounds

Unexposed group (UE)

(N = 60)

No history of participation in organized contact/collision sportsa or military combat service or training; asymptomatic, based on telephone screening questionsb (asked of both participant and informant) regarding current mood, behavior, or cognitive symptoms, as well as functional dependence; have at least 2 years of post-secondary education at a 4-year accredited college/university, or have an associate’s degree

History of TBI or concussion; history of formal diagnosis or treatment of psychiatric illness or cognitive impairment; body mass index (BMI) < 24

Former college football player group (COL)

(N = 60)

Played > 6 years of organized American football, with > 3 years at the college varsity level; played one of the following positionsc while in college: offensive lineman, defensive lineman, linebacker, offensive back or receiver, or defensive back (individuals whose primary position was kicker or quarterback were not included); no organized football or other contact/collision sport following college


Former professional football player group (PRO)

(N = 120)

Played ≥ 12 years of organized football, including > 3 in college and > 3 seasons in the NFL; played one of the following positionsc while in the NFL: offensive lineman, defensive lineman, linebacker, offensive back or receiver, or defensive back (individuals whose primary position was kicker or quarterback were not included)

  1. aThe unexposed participants must have never participated in any of the following organized sports at any level: American football, ice hockey, rugby, soccer (under age 14 allowed only if no heading the ball), lacrosse, wrestling, boxing, gymnastics, martial arts, and/or kickboxing
  2. bTelephone screening includes modified versions (for telephone) of the AD8 Dementia Screening Interview [98] and the Cognitive Change Index [99] (Items 1–12), as well as additional screening questions regarding mood, behavior, and cognitive functioning. These were administered to potential participants as well as their study partners
  3. cFollowing enrollment, when there was a question about an individuals’ position data reported during in-person interview, data from online resources were used to confirm position(s). Some positions may vary in future exposure modeling studies based on specific percentages of downs played at each position reported