Table 3.

Association between physical activity and risk of primary knee replacement.

	Total Population, n = 39,023		Sensitivity Analysis on Participants with Complete 2nd Followup Data, n = 27,323
	Hazard Ratio (95% CI)^†	p^†	Hazard Ratio (95% CI)^†	p^†
Total physical activity level
None (0)	1.00		1.00
Low (> 0–3)	1.16 (0.88, 1.52)	0.28	1.17 (0.85, 1.62)	0.33
Moderate (> 3–4)	1.13 (0.87, 1.46)	0.35	1.08 (0.79, 1.47)	0.64
High (> 4)	1.46 (1.13, 1.87)	0.003	1.47 (1.09, 1.96)	0.01
Trend test	1.04 (1.01, 1.07)	0.003	1.04 (1.01, 1.08)	0.01
Vigorous activity^*
None at all	1.00		1.00
1–2 times/week	1.42 (1.08, 1.86)	0.01	1.43 (1.06, 1.94)	0.02
≥ 3 times/week	1.24 (0.90, 1.71)	0.19	1.44 (1.02, 2.04)	0.04
Trend test	1.08 (1.00, 1.16)	0.05	1.11 (1.02, 1.21)	0.01
Less vigorous activity^*^††
None at all	1.00		1.00
1–2 times/week	1.09 (0.85, 1.40)	0.49	1.17 (0.88, 1.56)	0.28
≥ 3 times/week	1.19 (0.94, 1.52)	0.16	1.11 (0.83, 1.49)	0.49
Trend test	1.05 (0.98, 1.11)	0.15	1.03 (0.96, 1.11)	0.43
Walking^*^††
None at all	1.00		1.00
1–2 times/week	1.01 (0.77, 1.32)	0.95	0.95 (0.69, 1.31)	0.75
≥ 3 times/week	1.09 (0.89, 1.35)	0.41	1.04 (0.81, 1.33)	0.79
Trend test	1.02 (0.97, 1.08)	0.40	1.01 (0.95, 1.08)	0.75

↵† Adjusted for age, gender, body mass index, country of birth, occupational physical activity, and education level.
↵* Weekly frequency of physical activity undertaken for at least 20 minutes.
↵†† Analysis excluding those reporting vigorous activity.