Table 2 |
||
|
Reproductive factors in women and risk of rheumatoid arthritis, Denmark 1998 to 2003 |
||
| Number of patients/controls |
ORa (95% CI) |
|
|
|
||
| Age at menarche |
||
| ≤12 years |
85/145 |
1 (ref) |
| 13 years |
84/130 |
1.08 (0.73 to 1.61) |
| 14 years |
88/105 |
1.39 (0.93 to 2.08) |
| ≥15 years |
94/80 |
1.87 (1.23 to 2.85) |
| Trend test (p) |
0.002 |
|
| Number of live-born children |
||
| 0 |
67/86 |
1 (ref) |
| 1 |
81/85 |
1.10 (0.67 to 1.79) |
| 2 |
133/196 |
0.76 (0.48 to 1.21) |
| 3 |
63/84 |
0.81 (0.48 to 1.37) |
| ≥4 |
21/27 |
0.73 (0.36 to 1.51) |
| Trend test (p) |
0.15 |
|
| Spontaneous abortion |
||
| Never |
237/292 |
1 (ref) |
| Ever |
78/120 |
0.83 (0.59 to 1.18) |
| Test for homogeneity (p) |
0.29 |
|
| Breastfeedingb |
||
| Never |
19/18 |
1 (ref) |
| Ever |
279/374 |
0.70 (0.35 to 1.39) |
| Test for homogeneity (p) |
0.30 |
|
| Age at menopausec |
||
| <50 years |
37/34 |
1 (ref) |
| ≥50 years |
47/49 |
0.87 (0.46 to 1.65) |
| Test for homogeneity (p) |
0.68 |
|
| Oral contraceptive pills |
||
| Never |
116/165 |
1 (ref) |
| Ever |
249/312 |
1.24 (0.91 to 1.71) |
| Test for homogeneity (p) |
0.18 |
|
| Hormone replacement therapyd |
||
| Never |
328/436 |
1 (ref) |
| Ever |
36/37 |
1.08 (0.63 to 1.86) |
| Test for homogeneity (p) |
0.78 |
|
|
|
||
|
Due to missing values for some individuals, numbers do not always add up to 366 patients and 478 controls. aAdjusted for birth year and year or pseudo-year of RA diagnosis. bAmong women with at least one child. cAmong postmenopausal women without histories of hormone replacement therapy or surgical removal of the uterus or ovaries. dAmong women age 45 years or older. CI, confidence interval; OR, odds ratio; ref, reference. |
||
|
Pedersen et al. Arthritis Research & Therapy 2006 8:R133 doi:10.1186/ar2022 |
||
