Fig. 1

Graphs show a summary of sports played by CTE stage in a circular pie and doughnut plot, and the average timeline of athlete’s career across stage in a bar graph. A Sport and maximum level at which it was played is shown in the inner pie graph, while the distribution across stages is displayed in the outer doughnut plot for the 40 athletes. Some athletes reported playing multiple sports, but there is only one level for each sport. Inner graph shows a pie plot with colors denoting sport (red, football, n = 37; green, rugby, n = 3; orange, hockey, n = 2; purple, mixed martial arts (MMA), n = 1; blue, soccer, n = 1) and letters denoting the maximum level at which the athlete(s) played that sport (P, professional, n = 26; C, college, n = 12; S, semi-professional, n = 2; A, amateur, n = 2; and H, high school, n = 2). Outer graph shows a doughnut plot with the distribution across CTE stages for the corresponding pie. B Stacked bar graph shows average age (mean with standard deviation) athlete started playing (top line of blue box), years played (orange) and retirement age (top line of orange box), age at death (top line of yellow box) and age of symptom onset (purple horizontal marker) per CTE stage. There were significant differences between stages II and IV in age at death (a), years from retirement to death (b), age at symptom onset (c), and years from retirement to symptom onset (d). No differences were found between age athlete started playing contact sports, the number of years played, the age at retirement, or time from symptom onset to death across CTE stage. * p < 0.025, ** p < 0.005 KWDB