Table 3.

Risk differences in knee osteoarthritis and its related outcomes in ex-footballers compared with the general population

Knee OA outcomes	Crude	Model 1	RD % (95 % CI) Model 2	Model 3
Current knee pain	25.27 (22.14 to 28.40)	24.46 (21.30 to 27.62)	14.59 (11.32 to 17.87)	14.50 (7.97 to 21.03)
Total knee replacement	7.26 (5.39 to 9.13)	9.53 (7.44 to 11.63)	5.40 (3.63 to 7.17)	4.52 (1.39 to 7.65)
Nottingham Line Drawing Atlas (>2 osteophyte and >2 joint space narrowing)	28.81 (22.75 to 34.86)	37.49 (31.82 to 43.16)	31.11 (24.61 to 37.60)	31.45 (24.87 to 38.03)
Kellgren Lawrence (grade>3)	14.46 (9.35 to 19.57)	18.77 (13.46 to 24.08)	15.33 (9.56 to 21.09)	15.02 (9.17 to 20.88)
Kellgren Lawrence (grade>2)	21.98 (16.26 to 27.71)	27.61 (21.82 to 33.39)	21.21 (14.79 to 27.63)	20.75 (14.22 to 27.28)
Chondrocalcinosis	15.50 (10.89 to 20.11)	18.91 (14.04 to 23.77)	14.69 (9.56 to 19.82)	14.30 (9.18 to 19.41)

*RD adjusted for football status, age, BMI.

†RD adjusted for football status, age, BMI and injury.

‡RD adjusted for football status, age, BMI, nodal OA, injury, constitutional alignment, high-risk occupation, 2D:4D ratio, nodal OA, comorbidities.

BMI, body mass index; OA, osteoarthritis; RD, risk differences.