Table 2.

Relationship expressed as odds ratio (95% confidence of interval; adjusted for age and duration of retirement) of sports career-related concussions with symptoms of common mental disorders among former male professional athletes retired from football, ice hockey, and rugby.

Distress	Total	Football	Ice hockey	Rugby
0 Concussion	1.0	1.0	1.0	1.0
1 Concussion	0.9 (0.4–2.1)	0.6 (0.1–5.6)	na	1.1 (0.4–3.1)
2 or 3 Concussions	1.3 (0.7–2.4)	0.8 (0.2–3.2)	na	1.4 (0.6–3.0)
4 or 5 Concussions	1.4 (0.7–3.0)	2.6 (0.7–9.5)	na	0.9 (0.4–2.4)
6 or more Concussions	3.2 (1.5–6.9)	1.7 (0.1–20.0)	na	2.8 (1.2–6.8)
Anxiety and depression
0 Concussion	1.0	1.0	1.0	1.0
1 Concussion	0.8 (0.4–1.8)	na	0.4 (0.1–5.3)	1.4 (0.6–3.4)
2 or 3 Concussions	0.8 (0.4–1.5)	1.6 (0.5–5.0)	0.9 (0.1–9.0)	0.6 (0.3–1.2)
4 or 5 Concussions	1.4 (0.7–2.7)	2.2 (0.7–7.3)	na	1.2 (0.5–2.8)
6 or More concussions	2.4 (1.2–4.9)	9.8 (0.8–116.3)	2.0 (0.1–31.5)	2.0 (0.9–4.7)
Sleep disturbance
0 Concussion	1.0	1.0	1.0	1.0
1 Concussion	1.8 (0.8–3.9)	0.5 (0.1–5.4)	na	2.7 (1.1–6.9)
2 or 3 Concussions	1.9 (1.0–3.6)	1.5 (0.4–5.0)	na	1.6 (0.7–3.7)
4 or 5 Concussions	2.0 (1.0–4.2)	2.8 (0.8–10.2)	na	1.6 (0.6–4.0)
6 or More concussions	5.2 (2.4–11.2)	4.6 (0.5–42.8)	na	4.9 (2.0–12.2)
Adverse alcohol use
0 Concussion	1.0	1.0	1.0	1.0
1 Concussion	1.7 (0.8–3.7)	2.4 (0.4–13.5)	2.9 (0.5–17.3)	1.2 (0.4–3.9)
2 or 3 Concussions	1.4 (0.8–2.7)	1.3 (0.4–4.7)	0.3 (0.1–1.9)	2.4 (1.0–5.7)
4 or 5 Concussions	1.2 (0.5–2.4)	1.6 (0.4–6.5)	1.1 (0.1–12.5)	1.4 (0.5–3.8)
6 or More concussions	2.9 (1.3–6.2)	5.5 (0.6–51.4)	0.6 (0.1–14.3)	4.3 (1.7–11.3)
Comorbidity
0 Concussion	1.0	1.0	1.0	1.0
1 Concussion	1.1 (0.5–2.3)	0.9 (0.2–5.7)	0.4 (0.1–5.7)	1.5 (0.6–4.0)
2 or 3 Concussions	1.7 (0.9–3.0)	1.4 (0.4–4.2)	0.7 (0.1–7.1)	1.9 (0.9–4.2)
4 or 5 Concussions	1.5 (0.7–2.9)	1.4 (0.4–4.9)	na	1.6 (0.7–3.9)
6 or More concussions	3.8 (1.8–8.0)	11.1 (0.9–130.6)	1.6 (0.1–25.4)	3.9 (1.6–9.5)

na: Not applicable because of limited number of cases.