Table 2 Numbers, proportions and odds ratios (95% CI) for features in cases of ankylosing spondylitis compared with population controls

Specific features

N

%

N

%

OR

(95% CI)

N

%

N

%

OR

(95% CI)

Axial pain

39

52.7

31

10.5

9.8

(5.1, 18.9)

49

66.2

70

23.7

7.5

(4.0, 14.2)

Other spine diagnosis

16

21.6

17

5.7

5.1

(2.3, 11.3)

22

29.7

33

11.2

3.7

(1.9, 7.3)

Sciatica

5

6.8

8

2.7

2.8

(0.8, 9.3)

9

12.2

18

6.1

2.3

(0.9, 5.8)

Large joint symptom

14

18.9

25

8.5

2.7

(1.3, 5.8)

22

29.7

47

15.9

2.4

(1.3, 4.4)

Other joint symptom

5

6.8

4

1.4

6.0

(1.4, 25.5)

7

9.5

10

3.4

3.4

(1.2, 9.8)

Tendon disorders

9

12.2

12

4.1

3.4

(1.3, 8.7)

16

21.6

21

7.1

3.6

(1.7, 7.3)

Iritis

8

10.8

1

0.3

32.0

(4.0, 255.9)

12

16.2

3

1.0

16.0

(4.5, 56.7)

Urethral symptoms

2

2.7

1

0.3

–

–

3

4.1

8

2.7

1.5

(0.4, 6.0)

Fatigue

10

13.5

24

8.1

1.9

(0.8, 4.2)

12

16.2

39

13.2

1.3

(0.6, 2.8)

Inflamm. Bowel disease

7

9.5

4

1.4

7.0

(2.1, 23.9)

12

16.2

13

4.4

4.9

(2.0, 12.3)

Other Inflamm. arthritis

3

4.1

2

0.7

–

–

5

6.8

4

1.4

–

–

X-ray spine

6

8.1

0

0.0

–

–

7

9.5

2

0.7

–

–

X-ray pelvis

2

2.7

0

0.0

–

–

2

2.7

0

0.0

–

–

Full Blood Count

12

16.2

19

6.4

5.5

(1.8, 16.4)

15

20.3

23

7.8

9.2

(2.5, 33.4)

ESR

6

8.1

5

1.7

14.9

(1.7, 127.8)

7

9.5

6

2.0

9.7

(2.0, 47.9)

MRI scan

0

0.0

2

0.7

–

–

0

0.0

3

1.0

–

–

NSAIDs

52

70.3

60

20.3

12.9

(6.3, 26.8)

57

77.0

93

31.4

13.3

(5.9, 29.9)

Analgesics

37

50.0

43

14.5

6.0

(3.3, 10.8)

41

55.4

73

24.7

4.4

(2.4, 7.8)

Opioids

8

10.8

5

1.7

7.5

(2.2, 25.0)

10

13.5

8

2.7

7.9

(2.4, 25.7)

Tricyclic antidepressants

10

13.5

15

5.1

2.9

(1.3, 6.8)

12

16.2

18

6.1

3.2

(1.4, 7.3)

SSRI antidepressants

5

6.76

33

11.2

0.56

(0.2, 1.5)

12

16.22

13

4.39

4.91

(2.0, 12.3)