Table 4

Clinical outcomes by duration of breastfeeding

Breastfeeding 0 months

(n = 43)^a

Breastfeeding 1-12 months

(n = 72)^a

Breastfeeding > 12 months

(n = 19)^a

Mean age at diagnosis; years (SD)

63.6 (8.37)

62.8 (8.30)

64.2 (8.27)

Mean follow-up time; years (SD)

9.6 (3.4)

10.3 (3.7)

10.5 (2.8)

> 3 DMARDs used (%)

8/43(18.6)

17/71 (23.9)

5/19 (26.3)

DMARDs in combination (%)

14/43 (32.6)

32/71 (45.1)

8/19 (42.1)

Biological treatment ever (%)

10/43(23.3)

21/71 (29.6)

6/19 (31.6)

Documented radiographic erosions (ever) (%)

25/39 (64.1)

36/70 (51.4)

10/16 (62.5)

RF positive (%)

28/43 (65.1)

53/71 (74.6)

13/18 (72.2)

Mean HAQ at diagnosis (CI)^b

0.91 (0.64-1.18) (n = 21)

0.89 (0.69-1.09) (n = 39)

0.86 (0.47-1.25) (n = 10)

Mean HAQ 1 year after diagnosis (CI)^b

0.76 (0.49-1.03) (n = 24)

0.86 (0.66-1.06) (n = 44)

0.68 (0.32-1.03) (n = 14)

Mean HAQ 5 years after diagnosis (CI)^b

0.91 (0.68-1.14) (n = 31)

0.90 (0.72-1.09) (n = 49)

0.85 (0.48-1.22) (n = 12)

Mean HAQ 10 years after diagnosis (CI)^b

0.78 (0.50-1.06) (n = 16)

0.94 (0.76-1.13) (n = 38)

1.08 (0.70-1.45) (n = 9)

Cluster distribution (P = 0.88)

Severe RA (%)

8/31 (25.8)

15/48 (31.2)

3/11 (27.3)

Mild/moderate seropos RA (%)

13/31 (41.9)

20/48 (41.7)

6/11 (54.5)

Mild/moderate seroneg RA (%)

10/31 (32.3)

13/48 (27.1)

2/11 (18.2)

CI, confidence interval; HAQ, Health Assessment Questionnaire; RF, rheumatoid factor; SD, standard deviation. ^aIn case of missing data, numbers (n) indicated for each variable. ^bAdjusted for age at diagnosis.

Pikwer et al. Arthritis Research & Therapy 2012 14:R190   doi:10.1186/ar4021