| No. of participants | Person-years | No. of knee replacements | KRs per 10,000 person-years (crude rate) | Multivariate adjusted RR* (95% CI) |
---|---|---|---|---|---|
Body Mass Index, kg/m 2 | Â | ||||
<23.3 | 38,967 | 470,734 | 32 | 0.7 | 1 |
23.4-25.1 | 38,099 | 460,094 | 79 | 1.7 | 2.35 (1.55-3.54) |
25.2-27.2 | 38,918 | 469,847 | 93 | 2.0 | 2.58 (1.73-3.87) |
> = 27.3 | 37,807 | 455,912 | 226 | 5.0 | 6.16 (4.23-8.95) |
P (test for trend) | Â | Â | Â | Â | <0.0001 |
Physical activity at work | Â | ||||
Sedentary | 58,430 | 705,549 | 114 | 1.6 | 1 |
Moderate | 43,757 | 528,129 | 132 | 2.5 | 1.51 (1.18-1.95) |
Intermediate | 32,304 | 389,973 | 90 | 2.3 | 1.64 (1.24-2.17) |
Intensive | 19,118 | 230,737 | 94 | 4.1 | 2.41 (1.83-3.18) |
P (test for trend) | Â | Â | Â | Â | <0.0001 |
Physical activity at leisure | Â | ||||
Sedentary | 29,620 | 357,537 | 80 | 2.2 | 1 |
Moderate | 80,762 | 974,895 | 245 | 2.5 | 1.02 (0.79-1.31) |
Intermediate | 38,982 | 470,681 | 98 | 2.1 | 0.96 (0.71-1.30) |
Intensive | 4,350 | 52,544 | 6 | 1.1 | 0.84 (0.36-1.94) |
P (test for trend) | Â | Â | Â | Â | 0.668 |
Height | Â | ||||
< 174 | 44,106 | 532,390 | 126 | 2.4 | 1 |
175-178 | 36,438 | 439,896 | 111 | 2.5 | 1.38 (1.06-1.78) |
179-182 | 35,289 | 426,040 | 91 | 2.1 | 1.33 (1.01-1.76) |
> = 183 | 37,960 | 458,286 | 102 | 2.2 | 1.64 (1.25-2.15) |
P (test for trend) | Â | Â | Â | Â | 0.001 |
Smoking | Â | ||||
Never smoker | 46,945 | 566,770 | 126 | 2.2 | 1 |
Former smoker | 41,371 | 499,259 | 161 | 3.2 | 1.00 (0.79-1.27) |
Smoker | 65,479 | 790,606 | 143 | 1.8 | 0.82 (0.64-1.04) |
P (test for trend) | Â | Â | Â | Â | 0.092 |