Table 1 Sample characteristics of study population

Mean age (years)

54.3 ± 7.5

52.7 ± 9.5

44.0 ± 11.6

39.6 ± 11.5

** < 0.00^a

Mean ESR (mm/hr)

32.8 ± 21.4

27.9 ± 11.6

N/A

N/A

0.379^b

n (%)

n (%)

n (%)

n (%)

Gender

Female

14 (70)

19 (95)

11 (55)

16 (80)

**0.028^c

Male

6 (30)

1 (5)

9 (45)

4 (20)

Ethnicity

Malay

4 (20)

7 (35)

9 (45)

13 (65)

0.086^c

Chinese

11 (55)

7 (35)

9 (45)

5 (25)

Indian

5 (25)

6 (30)

2 (10)

2 (10)

Educational level

Tertiary

6 (30)

13 (65)

13 (65)

18 (90)

0.050^c

Secondary

14 (70)

6 (30)

7 (35)

2 (10)

Primary

0 (0)

1 (5)

0 (0)

0 (0)

Smoking status

Smoker

2 (10)

0 (0)

3 (15)

3 (15)

0.457^c

Former smoker

2 (10)

0 (0)

1 (5)

1 (5)

Non-smoker

16 (80)

20 (100)

16 (80)

16 (80)

RA disease duration

 < 5

8 (40)

7 (35)

N/A

N/A

0.587^c

5–10

6 (30)

9 (45)

N/A

N/A

 > 10 years

6 (30)

4 (20)

N/A

N/A

RA medication

Corticosteroid

NSAIDs

Conventional DMARDs

Biologic DMARDs

Combination

1(5)

3(15)

7(35)

0(0)

6(30)

0(0)

2(10)

9(40)

1(5)

5(25)

N/A

N/A

N/A

N/A

N./A

N/A

N/A

N/A

N/A

N/A

0.632^c

PD status

Localised Pd

17 (85)

N/A

14 (70)

N/A

0.110^c

Generalised Pd

3 (15)

N/A

6 (30)

N/A