Table 1 Patient characteristics

Mean ± SD

Age, years

69.5 ± 10.2

Body Mass Index, kg/m ²

28.4 ± 4.9

WOMAC Score

n missing = 1

44.6 ± 20.3

AMICAL Score

n missing = 4

235.6 ± 73.8

HAQ-DI Score

n missing = 4

1.14 ± 0.65

n

%

Sex, female

117

80

Smoking history, pack years

 0

93

64

 >0, ≤ 5

26

18

 >5, ≤ 10

8

5

 >10, ≤ 15

2

1

 ≥15

17

12

Diabetes

41

28

Hypertension

76

52

Education

 Less than elementary (<6 years)

25

17

 Elementary school (6 years)

29

20

 Middle-school (9 years)

31

21

 High-school (12 years)

39

27

 College level or above

22

15

Occupation type

 Manual labor

67

47

 Non-managerial office work

30

21

 Managerial

22

15

 Home

25

17

Estimated income quintile

 I or II

21

14

 III

30

21

 IV

31

21

 V

64

44

Paternal education

 Less than elementary (<6 years)

48

36

 Elementary school (6 years)

55

41

 Middle-school (9 years)

12

9

 High-school (9 years)

7

5

 College level or above

13

9

Maternal education

 Less than elementary (<6 years)

66

45

 Elementary school (6 years)

53

36

 Middle-school (9 years)

7

5

 High-school (9 years)

11

8

 College level or above

4

3

Paternal occupation

 Manual labor

111

79

 Non-managerial office work

10

7

 Managerial

20

14

Maternal occupation

 Manual labor

36

25

 Non-managerial office work

9

6

 Managerial

4

3

 Home

94

66