Table 1.
Summary of studies of retired athletes.
| First author | Year published | Primary study site | Total N | Played before age 12 | Age (years) | Sample/outcome measures | AFE binary vs. continuous | Positive Findings | Negative Findings |
|---|---|---|---|---|---|---|---|---|---|
| Stamm (80) | 2015 | BU CTE Center | 42 | 21 |
M = 52, SE = 1 |
Former NFL Players (DETECT)/Neuropsychological Testing | Binary | Yes | Yes |
| Stamm (81) | 2015 | BU CTE Center | 40 | 20 |
M = 52, SD = 6 |
Former NFL Players (DETECT)/Neuroimaging (DTI; Corpus Callosum) | Binary | Yes | Yes |
| Schultz (82) | 2018 | BU CTE Center | 86 | Not reported |
M = 55, SD = 8 |
Former NFL Players (DETECT)/Neuroimaging (Thalamic Volume) | Continuous | Yes | Yes |
| Kaufmann (83) | 2021 | BU CTE Center | 63 | Not reported |
M = 56, SD = 8 |
Former NFL Players (DETECT)/Neuroimaging (Cortical Thickness) | Continuous | Yes | Yes |
| Alosco (92) | 2017 | BU CTE Center | 214 | 101 |
M = 51, SD = 13 |
Former Amateur and Professional Football (LEGEND)/Neuropsychological Testing and Self-Report Measures | Binary and Continuous | Yes | Yes |
| Montenigro (93) | 2017 | BU CTE Center | 93 | Not reported |
M = 47, SD = 14 |
Former High School and Collegiate Football (LEGEND)/Neuropsychological Testing and Self-Report Measures | Binary | No | Yes |
| Alosco (94) | 2018 | BU CTE Center | 211 | 84 |
M = 63, SD = 18 |
Deceased Former Amateur & Professional Football (UNITE)/Post-Mortem Neuropathology, Symptoms, Age of Onset of Problems | Binary and Continuous | Yes | Yes |
| Solomon (91) | 2016 | Vanderbilt University | 45 | Not reported |
M = 47, SD = 9 |
Former NFL Players/Neuroimaging, Neuropsychological Testing, Self-Report Measures | Continuous | No | Yes |
| Roberts (71) | 2019 | Harvard University | 3,506 | Not reported |
M = 53, SD = 14 |
Former NFL Players (Football Players Health Study)/Self-Report Measures | Binary and Continuous | No | Yes |
| Iverson (86) | 2020 | Harvard Medical School | 123 | 62 |
M = 45, SD = 6 |
Former high school football players/Self-Report Measures | Binary and Continuous | No | Yes |
| Iverson (85) | 2021 | Harvard Medical School | 186 | 87 |
M = 52, SD = 11 |
Former high school football players/Self-Report Measures | Binary and Continuous | No | Yes |
| Bryant (122) | 2020 | Cleveland Clinic Lou Ruvo Center for Brain Health | Active fighters (n = 442); Retired fighters (n = 64) | Not reported | Active fighters M = 29 SD = 5; Retired fighters; M = 48, SD = 10 |
Male and female licensed professional fighters (boxers, mixed martial artists, and martial artists); Professional Fighters Brain Health Study/Neuroimaging, Neuropsychological Testing, Balance, Self-Report Measures | Continuous | Yes | Yes |
| Hunzinger (121) | 2021 | University of Delaware | 1,034 (Active and Retired) | 753 |
M = 32, SD = 11 |
Current and former male and female rugby players/Self-Report Measures | Binary and Continuous | No | Yes |
Full summaries of these articles are in the online supplement. BU, Boston University; CTE, Chronic traumatic encephalopathy; NFL, National Football League; DETECT, Diagnosing and Evaluating Traumatic Encephalopathy Using Clinical Tests; LEGEND, Longitudinal Examination to Gather Evidence of Neurodegenerative Disease; UNITE, Understanding Neurologic Injury and Traumatic Encephalopathy; AFE, age of first exposure; DTI, diffusion tensor imaging.