Associations between preceding respiratory tract diseases (at least 2 yrs before index date) and incident RA.
| Respiratory Tract Disease | n (%) | Adjusteda OR for RA (95% CI) | |||
|---|---|---|---|---|---|
| RA Cases, n = 741 | Controls, n = 2223 | All RA Cases, n = 741 | Seropositive RA Cases, n = 426b | Seronegative RA Cases, n = 303 | |
| Any respiratory tract disease | 346 (47) | 931 (42) | 1.16 (0.95–1.42) | 1.14 (0.87–1.50) | 1.24 (0.92–1.69) |
| Acute upper | 171 (23) | 432 (19) | 1.25 (0.98–1.60) | 1.24 (0.88–1.74) | 1.36 (0.94–1.97) |
| Acute sinusitis | 45 (6) | 86 (4) | 1.61 (1.05–2.45) | 1.89 (1.03–3.49) | 1.43 (0.77–2.64) |
| Acute pharyngitis | 80 (11) | 192 (9) | 1.34 (0.97–1.85) | 1.18 (0.75–1.85) | 1.68 (1.02–2.74) |
| Chronic upper | 104 (14) | 286 (13) | 1.18 (0.89–1.56) | 1.12 (0.76–1.65) | 1.30 (0.85–2.00) |
| Chronic sinusitis | 42 (6) | 68 (3) | 2.16 (1.39–3.35) | 1.55 (0.83–2.88) | 3.23 (1.65–6.32) |
| Chronic rhinitis/pharyngitis | 17 (2) | 33 (1) | 1.77 (0.95–3.27) | 2.46 (1.01–5.99) | 1.56 (0.63–3.88) |
| Acute lower | 78 (11) | 153 (7) | 1.37 (0.98–1.91) | 1.46 (0.94–2.28) | 1.30 (0.76–2.20) |
| Pneumonia | 38 (5) | 87 (4) | 1.17 (0.76–1.81) | 1.00 (0.54–1.87) | 1.53 (0.81–2.86) |
| Chronic lower | 121 (16) | 263 (12) | 1.32 (1.01–1.74) | 1.24 (0.85–1.81) | 1.49 (0.99–2.23) |
| Asthma | 93 (13) | 193 (9) | 1.39 (1.03–1.87) | 1.35 (0.89–2.05) | 1.49 (0.96–2.31) |
| COPD | 43 (6) | 83 (4) | 1.35 (0.88–2.06) | 1.20 (0.67–2.15) | 1.55 (0.82–2.93) |
↵a Respiratory codes at least 2 years before index date of RA or matched date. Reference group was individuals with no respiratory tract disease codes of any kind prior to index date. Adjusted for age, sex, EHR history, enrollment year, race/ethnicity, education, BMI, smoking status, and pack-years.
↵b RA cases without RA-related autoantibody test results (n = 12) could not be classified by serostatus. Their 36 matched controls were also removed from these analyses. Values in bold are statistically significant. COPD: chronic obstructive pulmonary disease; EHR: electronic health record; RA: rheumatoid arthritis.