Table 5.
Odds ratio of ACPA-positive, ACPA-negative RA according to type of medication, among women aged 50–70
| ACPA status | Use of PMH | Estrogen only | Estrogen + progestogensa | ||
|---|---|---|---|---|---|
| Ca/Co | OR 95 % CIb | Ca/Co | OR 95 % CIb | ||
| ACPA-positive | Ever | 57/165 | 1.1 (0.7–1.5) | 33/139 | 0.7 (0.5–1.1) |
| Current | 15/50 | 0.8 (0.5–1.6) | 7/55 | 0.3 (0.1–0.7)c | |
| Past | 42/114 | 1.2 (0.8–1.8) | 26/83 | 1.0 (0.6–1.6) | |
| Never | 209/626 | 1.0 | 209/626 | 1.0 | |
| Missing | 4/5 | – | 4/5 | – | |
| ACPA-negative | Ever | 31/165 | 1.0 (0.7–1.6) | 24/139 | 1.0 (0.6–1.6) |
| Current | 9/50 | 0.8 (0.3–1.8) | 9/55 | 0.9 (0.4–2.0) | |
| Past | 22/114 | 1.1 (0.7–1.9) | 15/83 | 1.1 (0.6–2.0) | |
| Never | 109/626 | 1.0 | 109/626 | 1.0 | |
| Missing | 0/5 | – | 0/5 | – | |
EIRA, Sweden, 2006–2011
ACPA antibodies to citrullinated peptides antigens, RA rheumatoid arthritis, PMH postmenopausal hormone, Ca/Co number of cases/controls, OR odds ratio, CI confidence interval
aThe estrogen plus progestogen group includes both combined and sequential regimens
bAdjusted by age, residential area and smoking (pack-years)
c p = 0.0078