Demographics and rheumatic disease characteristics of patients with history of COVID-19 infection
| Characteristic | All rheumatic disease patients (N=280) | Breakthrough COVID-19 infection (N=116) | Non-breakthrough COVID-19 infection (N=164) | P value |
| Age at time of COVID-19 symptom onset in years, mean±SD | 52 (15) | 53 (15) | 51 (16) | 0.48 |
| Age at time of survey in years, mean±SD | 53 (15) | 53 (15) | 52 (16) | 0.68 |
| Female, n (%) | 223 (80) | 93 (80) | 130 (79) | 0.88 |
| Race, n (%) | ||||
| Asian | 12 (4) | 5 (4) | 7 (4) | 1.00 |
| Black | 20 (7) | 4 (3) | 16 (10) | 0.06 |
| White | 230 (82) | 101 (87) | 129 (79) | 0.08 |
| Other | 15 (5) | 6 (5) | 9 (5) | 1.00 |
| Unknown | 7 (3) | 3 (3) | 4 (2) | 1.00 |
| Hispanic or Latinx ethnicity | 27 (10) | 8 (7) | 19 (12) | 0.15 |
| Smoking status | 0.65 | |||
| Current | 4 (1) | 2 (2) | 2 (1) | |
| Former | 72 (26) | 27 (23) | 45 (27) | |
| Never | 203 (73) | 87 (75) | 116 (71) | |
| SARD category* | 0.33 | |||
| Inflammatory arthritis | 165 (59) | 61 (53) | 104 (63) | |
| Connective tissue disease | 68 (24) | 30 (26) | 38 (23) | |
| Vasculitis | 26 (9) | 13 (11) | 13 (8) | |
| Multiple | 9 (3) | 5 (4) | 4 (2) | |
| Other | 12 (4) | 7 (6) | 5 (3) | |
| Immunomodulatory medications | ||||
| cs DMARDs | ||||
| Antimalarial (includes hydroxychloroquine and chloroquine) | 64 (23) | 34 (29) | 30 (18) | 0.04 |
| Methotrexate | 60 (21) | 27 (23) | 33 (20) | 0.56 |
| Mycophenolate mofetil/mycophenolic acid | 21 (8) | 14 (12) | 7 (4) | 0.02 |
| Other csDMARD† | 25 (9) | 14 (12) | 11 (7) | 0.14 |
| Targeted synthetic DMARD (JAK inhibitor) | 13 (5) | 7 (6) | 6 (4) | 0.40 |
| Biologic DMARDs | ||||
| Anti-CD20 monoclonal antibody | 23 (8) | 14 (12) | 9 (5) | 0.08 |
| TNF inhibitor | 63 (22) | 28 (24) | 35 (21) | 0.66 |
| Other biologic DMARD‡ | 35 (13) | 15 (13) | 20 (12) | 0.86 |
| Baseline glucocorticoid use at COVID-19 onset | 51 (18) | 24 (21) | 27 (16) | 0.43 |
| Dose (prednisone-equivalent, daily mg), median (IQR) | 9 (5–15) | 8 (5–20) | 10 (5–15) | 0.43 |
| Comorbidities | ||||
| Obesity | 58 (21) | 17 (15) | 41 (25) | 0.04 |
| Hypertension | 64 (23) | 28 (24) | 36 (22) | 0.67 |
| Asthma | 49 (18) | 23 (20) | 26 (16) | 0.43 |
| Obstructive sleep apnoea | 21 (8) | 7 (6) | 14 (9) | 0.50 |
| Coronary artery disease | 18 (6) | 6 (5) | 12 (7) | 0.62 |
| Diabetes | 16 (6) | 7 (6) | 9 (5) | 1.00 |
| Heart failure | 6 (2) | 2 (2) | 4 (2) | 1.00 |
| Chronic kidney disease | 12 (4) | 7 (6) | 5 (3) | 0.24 |
| Chronic obstructive pulmonary disease | 4 (1) | 2 (2) | 2 (1) | 1.00 |
| Interstitial lung disease/pulmonary fibrosis | 9 (3) | 5 (4) | 4 (2) | 0.50 |
| Solid tumour | 4 (1) | 1 (1) | 3 (2) | 0.64 |
| Comorbidity count, median (IQR) | 1 (0–2) | 1 (0–1) | 1 (0–2) | 0.68 |
*For patients who reported multiple SARD diagnoses, those who reported inflammatory arthritis in addition to either lupus or myositis were classified as having a ‘connective tissue disease (CTD)’ given that inflammatory arthritis can be a component of CTD. Patients who listed both polymyalgia rheumatica and rheumatoid arthritis were classified as having ‘inflammatory arthritis’. Patients with multiple SARDs that can coexist (eg, psoriatic arthritis and lupus) were classified as having multiple SARDs. In the case of missing data or unanswered survey questions regarding rheumatic disease diagnosis or treatment, manual review of the EHR was performed to fill in this missing data.
†Other conventional synthetic DMARD includes leflunomide, azathioprine, sulfasalazine, apremilast, cyclosporine and tacrolimus
‡Other biological DMARD includes IL-6 receptor inhibitor, B-cell activating factor inhibitor, IL-23 inhibitor, IL-17 inhibitor, IL-12/IL-23 inhibitor, IL-1 inhibitor and CTLA-4 immunoglobulin
csDMARD, conventional synthetic disease-modifying antirheumatic drug; EHR, electronic health record; JAK, janus kinase; SARD, systemic autoimmune rheumatic disease.