Table 2.
Characteristics of the 741 incident Mass General Brigham Biobank RA cases and 2,223 matched controls with at least 5 years of EHR history, at index date of RA diagnosis
| Characteristic | RA cases (n=741) | Controls (n=2,223) | p-value |
|---|---|---|---|
|
| |||
| Age in years, median (IQR) | 55 (45,63) | 56 (47,63) | 0.46* |
| Female sex, n (%) | 563 (76) | 1689 (76) | 1.00* |
| EHR history in years, median (IQR) | 12 (8,16) | 11 (8,16) | 0.004* |
| Enrollment year, median (IQR) | 2016 (2014,2017) | 2016 (2014,2017) | 0.04 |
| White, non-Hispanic race, n (%) | 597 (81) | 2015 (91) | <0.001 |
| Education college or higher, n (%)** | 485 (65) | 1600 (72) | <0.001 |
| BMI, kg/m2, n (%) | <0.001 | ||
| <20 | 24 (3) | 124 (6) | |
| 20–25 | 221 (30) | 753 (34) | |
| 25–30 | 216 (29) | 688 (31) | |
| 30+ | 280 (38) | 658(30) | |
| Smoking status, n (%)** | <0.001 | ||
| Never | 366 (49) | 1240 (56) | |
| Past | 303 (41) | 862 (39) | |
| Current | 72 (10) | 121 (5) | |
| Smoking pack-years, n(%) | <0.001 | ||
| 0 (nonsmoker) | 366 (49) | 1240 (56) | |
| 1–10 | 178 (24) | 579 (26) | |
| >10 | 197 (27) | 404 (18) | |
BMI = body mass index, CI = confidence interval, EHR = electronic health record, IQR = interquartile range, kg = kilograms, m = meters, RA = rheumatoid arthritis
*
Matching factor
**
As of Mass General Brigham Biobank enrollment