Table 2

Subgroup

Thrombotic events

Rate of events/1,000 person-years

Rate ratios (95% CI)

P value


Current prednisone

None

52

10.6

1.0 (Ref. Gp)

1 to 9 mg/day

40

16.4

1.6 (1.1 to 2.4)

0.025

10 to 19 mg/day

49

34.3

3.3 (2.2 to 4.8)

<0.0001

20+ mg/day

43

71.8

6.5(4.3 to 9.8)

<0.0001

Cumulative prednisone dose

None

29

13.1

1.0 (Ref. Gp)

<1 year (10 mg/day)

37

23.8

1.6 (1.0 to 2.6)

0.075

1 to 3 years (10 mg/day)

30

19.0

1.8 (1.1 to 3.1)

0.026

3 to 10 years (10 mg/day)

45

25.5

3.0 (1.8 to 5.2)

<0.0001

>10 years (10 mg/day)

9

24.3

3.7 (1.5 to 9.4)

0.0056

Current HCQ

No

95

29.0

1.0 (Ref. Gp)

Yes

90

14.6

0.5 (0.4 to 0.7)

<0.0001

HCQ use

Never

57

32.2

1.0 (Ref. Gp)

Past (not current)

27

27.6

0.9 (0.6 to 1.5)

0.81

<6 consecutive months

16

20.0

0.6 (0.3 to 1.0)

0.056

>6 consecutive months

64

13.8

0.5 (0.3 to 0.7)

0.0003

NSAID use

No

146

21.6

1.0 (Ref. Gp)

Yes

37

13.9

0.6 (0.4 to 0.9)

0.017

Aspirin use

No

137

17.9

1.0 (Ref. Gp)

Yes

49

28.0

1.6 (1.2 to 2.3)

0.0038


Petri Arthritis Research & Therapy 2012 14(Suppl 3):A52   doi:10.1186/ar3986