Table 5 Conditional logistic regression model for women: most parsimonious model

Knee pain during childhood

No (R)

623

361

262

1.00

-

Yes

59

41

18

<0.05

2.08

1.01 to 4.26

Knee OA in relatives

No (R)

408

216

192

1.00

-

Yes

205

142

63

<0.001

2.17

1.40 to 3.37

Malalignment of the knee

No (R)

624

336

288

1.00

-

Yes

90

83

7

<0.001

11.54

4.65 to 28.66

Body mass index

18.5 to <25 kg/m² (R)

255

97

158

1.00

-

≥25 to <30 kg/m²

249

163

86

<0.001

3.21

2.09 to 4.96

≥30 to <35 kg/m²

149

107

42

<0.001

3.55

2.12 to 5.94

≥35 to <40 kg/m²

55

49

6

<0.001

11.58

4.38 to 30.63

≥40 kg/m²

23

20

3

<0.001

17.65

4.50 to 69.23

Smoking

No (R)

391

255

136

1.00

-

Yes, <9 package-years

117

63

54

NS

0.69

0.40 to 1.17

Yes, 9 to 20 package-years

114

64

50

NS

1.16

0.67 to 2.03

Yes, >20 package-years

115

54

61

<0.01

0.43

0.26 to 0.73

Occupation: kneeling or squatting

No (R)

388

212

176

1.00

-

Yes, <3,542 hours/life

109

62

47

NS

1.50

0.83 to 2.69

Yes, 3,542 to 8,934 hours/life

110

68

42

NS

1.36

0.78 to 2.37

Yes, >8,934 hours/life

109

85

24

<0.01

2.52

1.35 to 4.68

Occupation: sitting

No (R)

88

60

28

1.00

-

Yes, <16,032 hours/life

209

127

82

NS

0.72

0.37 to 1.40

Yes, 16,032 to 33,119 hours/life

209

122

87

<0.05

0.51

0.26 to 0.99

Yes, >33,119 hours/life

210

118

92

<0.01

0.39

0.20 to 0.76

Occupation: lifting and carrying

No (R)

263

139

124

1.00

-

sometimes

65

37

28

NS

0.88

0.44 to 1.77

Yes, <1,088 tons/life

122

69

53

NS

0.69

0.38 to 1.24

Yes, ≥1,088 tons/life

121

92

29

<0.01

2.13

1.14 to 3.98

Sports with risk for unapparent trauma

No (R)

570

342

228

1.00

-

Yes, <1,440 hours/life

81

41

40

NS

0.92

0.48 to 1.75

Yes, ≥1,440 hours/life

78

50

28

<0.01

2.47

1.31 to 4.65