Table 4 Numbers, proportions and odds ratios (95% CI) for composite features in the three years before diagnosis of AS/index date

Composite features

N

%

N

%

OR

(95% CI)

N

%

OR

(95% CI)

Axial pain within 30 days of NSAID

29

39.2

20

6.8

10.4

(4.9, 22.1)

45

26.6

1.8

(0.9, 3.6)

Axial pain within 360 days of large joint symptom

9

12.2

8

2.7

7.2

(2.2, 24.0)

11

6.5

1.5

(0.5, 4.2)

Axial pain separated by 180 days

17

23.0

7

2.4

12.7

(4.7, 34.6)

17

10.1

2.8

(1.3, 5.9)

Axial pain separated by 360 days

10

13.5

5

1.7

8.0

(2.7, 23.4)

11

6.5

2.2

(0.8, 5.6)

Axial pain, without ever sciatica

36

48.7

27

9.1

8.9

(4.7, 16.9)

82

48.5

1.1

(0.6, 1.9)

Tendon disorders separated by 180 days

1

1.4

1

0.3

–

–

0

0.0

–

–

Tendon disorder within 360 days of axial pain

6

8.1

2

0.7

21.7

(2.6, 181.5)

5

3.0

2.7

(0.8, 9.0)

FBC within 90 days of axial pain

7

9.5

4

1.4

8.6

(2.2, 33.6)

10

5.9

2.2

(0.7, 7.3)

ESR within 180 days of axial pain

4

5.4

0

0.0

–

–

1

0.6

–

–

Iritis within 360 days of axial pain

5

6.8

0

0.0

–

–

0

0.0

–

–