Baseline characteristics of the postmenopausal women included in the study
| All n=2878 | Early menopause n=437 | Usual menopause n=2441 | P value | |
| Age at enrolment | 60.4±8.3 | 58.0±9.5 | 60.8±8.0 | <0.001 |
| Age at disease onset | 49.5±11.0 | 46.2±11.9 | 50.0±10.7 | <0.001 |
| Disease duration (year) | 8.6±7.7 | 9.2±8.5 | 8.5±7.6 | 0.142 |
| Education, high school or more | 1058 (36.8) | 187 (42.9) | 855 (35.3) | 0.002 |
| Monthly income, US$≥1700 | 1197 (41.6) | 187 (42.9) | 995 (41.0) | 0.492 |
| Current smoker | 77 (2.7) | 16 (3.7) | 61 (2.5) | 0.408 |
| Current alcohol drinking | 364 (12.7) | 69 (15.8) | 295 (12.1) | 0.081 |
| BMI (kg/m2) | 22.8±3.6 | 22.9±3.4 | 23.1±3.2 | 0.212 |
| Reproductive variables | ||||
| Age at menopause (years) | 48.6±5.0 | 39.7±4.1 | 50.2±3.1 | <0.001 |
| Time since menopause (years) | 11.8±8.7 | 18.3±9.9 | 10.6±7.9 | <0.001 |
| Causes of menopause | <0.001 | |||
| Natural menopause | 2452 (85.2) | 217 (49.7) | 2235 (91.6) | |
| Surgical menopause | 381 (13.2) | 205 (46.9) | 176 (7.2) | |
| Medical-induced menopause | 45 (1.6) | 15 (3.4) | 30 (1.2) | |
| Age at menarche (years) | 16.2±2.1 | 16.0±2.1 | 16.2±2.1 | 0.083 |
| Number of pregnancies | 4.4±2.2 | 4.3±2.4 | 4.4±2.2 | 0.422 |
| Number of deliveries | 2.7±1.4 | 2.6±1.5 | 2.7±1.3 | 0.531 |
| Breast feeding | 2486 (86.4) | 356 (81.5) | 2130 (87.3) | 0.001 |
| Duration of breast feeding (months) | 39.0±31.6 | 39.4±31.0 | 38.9±31.8 | 0.800 |
| Use of HRT | 0.096 | |||
| Never used | 2199 (76.4) | 314 (71.9) | 1885 (77.2) | |
| Previous use of HRT | 520 (18.1) | 96 (22.0) | 424 (17.4) | |
| Current use of HRT | 131 (4.6) | 23 (5.3) | 108 (4.4) | |
| Patient-reported outcomes | ||||
| Morning stiffness >1 hour | 2681 (93.2) | 412 (94.3) | 2269 (93.0) | 0.574 |
| Pain VAS | 41.5±28.4 | 43.9±29.2 | 41.1±28.3 | 0.055 |
| Global assessment VAS | 43.9±26.2 | 46.7±26.9 | 43.4±26.1 | 0.016 |
| Fatigue VAS | 46.4±29.4 | 50.0±29.9 | 45.7±29.2 | 0.005 |
| Sleep disturbance VAS | 29.9±30.1 | 34.4±32.6 | 29.1±29.6 | 0.002 |
| EQ-5D–VAS | 62.5±19.9 | 59.9±22.2 | 63.0±19.5 | 0.006 |
| EQ-5D utility value | 0.6±0.3 | 0.6±0.3 | 0.6±0.3 | 0.096 |
| HAQ-DI | 0.8±0.7 | 0.9±0.7 | 0.8±0.7 | 0.237 |
| Physician’s VAS | 27.4±18.8 | 27.7±19.7 | 27.4±18.7 | 0.747 |
| Laboratory findings | ||||
| Seropositivity | 2188/2301 (95.1) | 321/342 (93.9) | 1867/1959 (95.3) | 0.277 |
| RF-positive | 1413/1865 (75.8) | 203/292 (69.5) | 1210/1573 (76.9) | 0.007 |
| RF titre | 109.3±209.5 | 102.4±178.4 | 110.6±214.9 | 0.491 |
| ACPA-positive | 1759/2117 (61.1) | 254/315 (80.6) | 1505/1802 (83.5) | 0.222 |
| ESR | 31.6±24.9 | 32.2±26.3 | 31.4±24.7 | 0.576 |
| CRP | 1.1±2.3 | 1.0±1.9 | 0.9±1.5 | 0.160 |
| 28-tender joint count | 4.4±9.6 | 4.6±5.8 | 4.1±5.2 | 0.046 |
| 28-swollen joint count | 2.6±11.9 | 2.4±3.7 | 2.1±3.2 | 0.047 |
| SDAI | 14.8±19.0 | 15.4±11.7 | 13.9±10.0 | 0.011 |
| CDAI | 14.0±18.5 | 14.5±11.1 | 13.1±9.7 | 0.018 |
| DAS28 | 4.0±1.3 | 4.1±1.4 | 3.9±1.3 | 0.018 |
| Moderate to high disease activity | ||||
| SDAI >11 | 1448 (52.9) | 244 (58.2) | 1202 (51.9) | 0.017 |
| Erosion on hand X-ray | 539/1,197 (45.0) | 85 (47.0) | 454 (44.7) | 0.627 |
Values are presented as mean (SD) or number (%).
ACPA, anticitrullinated protein antibody; BMI, body mass index; CDAI, Clinical Disease Activity Index; CRP, C reactive protein; DAS28, Disease Activity Score using 28 joint counts; DMARD, disease-modifying antirheumatic drug; EQ-5D, EuroQol-5D; ESR, erythrocyte sedimentation rate; HAQ-DI, Health Assessment Questionnaire–Disability Index; HRT, hormone replacement therapy; NSAID, non-steroidal anti-inflammatory drug; RF, rheumatoid factor; SDAI, Simplified Disease Activity Index; VAS, visual analogue scale.