Table 1

Characteristics of the study population

Controls

Knee OA cases

Hip OA cases


Number

967

1042

1006

Age, years (SD)

63.5 (8.5)

68.1 (7.4)*

67.6 (7.1)*

BMD, z-score (SD)

0.6 (1.2)

1.0 (1.3)*

1.0 (1.3)*

Women, %

47.2

48.6

50.5

BMI (kg/m2), % prevalence

<25

32.7

9.5

19.2%

25 to 30

43.2

36.0*

41.7*

>30

24.1

54.5*

39.2*

Nodal OA, % prevalence

10.3

28.8*

24.6*

Injury (knee or hip), % prevalence

16.8

32.8*

22.2*

Occupational risk factors, % prevalence

None

61.8*

48.8

57.2

1 OA risk factor

12.5

14.3

12.1

2 OA risk factors

11.7

14.1

12.4

3+ OA risk factors

14.1

22.7*

18.3*


The number per group, mean (SD) or percentage prevalence are presented. *P <0.01, cases versus controls. OA, osteoarthritis; BMD, bone mineral density.

Muthuri et al. Arthritis Research & Therapy 2013 15:R52   doi:10.1186/ar4214

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