Skip to main content

Advertisement

Table 4 Crude rate and relative risk of KR due to primary OA in 161,700 Norwegian women

From: Risk factors for knee replacement due to primary osteoarthritis, a population based, prospective cohort study of 315,495 individuals

  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  
<21.6 40,526 489,541 35 0.7 1
21.7-23.5 39,562 477,775 73 1.5 1.93 (1.29-2.89)
23.6-26.1 40,691 491,052 177 3.6 3.92 (2.72-5.64)
> = 26.2 40,911 491,705 608 12.4 11.06 (7.83-15.62)
P (test for trend)      <0.0001
Physical activity at work  
Sedentary 46,050 555,499 201 3.6 1
Moderate 84,368 1,017,358 498 4.9 1.18 (1.00-1.40)
Intermediate 27,744 334,751 149 4.5 1.30 (1.05-1.61)
Intensive 3,343 40,230 45 11.2 2.29 (1.65-3.18)
P (test for trend)      <0.0001
Physical activity at leisure  
Sedentary 31,322 377,346 190 5.0 1
Moderate 113,127 113,127 624 55.2 0.99 (0.84-1.16)
Intermediate 16,204 16,204 75 46.3 0.92 (0.70-1.21)
Intensive 968 11,687 4 3.4 1.72 (0.64-4.65)
P (test for trend)      0.797
Height  
< 161 44,123 531,632 325 6.1 1
162-165 42,320 510,399 238 4.7 1.10 (0.93-1.30)
166-169 38,461 464,179 150 3.2 0.93 (0.77-1.14)
> = 170 36,791 443,925 180 4.1 1.48 (1.23-1.80)
P (test for trend)      0.003
Smoking  
Never smoker 65,929 794,420 526 6.6 1
Former smoker 31,174 376,055 163 4.3 0.81 (0.68-0.96)
Smoker 64,597 779,720 204 2.6 0.66 (0.56-0.78)
P (test for trend)      <0.0001
  1. *Adjusted for age at screening, height, smoking habits, BMI and physical activity at work, and at leisure time.