Baseline characteristics of all patients who underwent SARS-CoV-2 testing in Korean nationwide cohort (N=132 316)
| Characteristic | Entire cohort | Entire cohort | ||
| None | Current use of PPI | Past use of PPI | ||
| Total, N (%) | 132 316 | 111 911 | 14 163 | 6242 |
| Age, years, mean (SD) | 48.0 (19.7) | 46.7 (19.6) | 56.3 (18.9) | 52.2 (18.7) |
| Sex, n (%) | ||||
| Male | 67 480 (51.0) | 57 408 (51.3) | 7070 (49.9) | 3002 (48.1) |
| Female | 64 836 (49.0) | 54 503 (48.7) | 7093 (50.1) | 3240 (51.9) |
| Region of residence, n (%) | ||||
| Rural | 59 364 (44.1) | 49 760 (44.5) | 5927 (41.9) | 2677 (42.9) |
| Urban | 73 952 (55.9) | 62 151 (55.5) | 8236 (58.2) | 3565 (57.1) |
| History of diabetes mellitus, n (%) | 20 419 (15.4) | 15 235 (13.6) | 3840 (27.1) | 1344 (21.5) |
| History of cardiovascular disease, n (%) | 17 392 (13.1) | 12 667 (11.3) | 3621 (25.6) | 1104 (17.7) |
| History of cerebrovascular disease, n (%) | 11 986 (9.1) | 9183 (8.2) | 2145 (15.2) | 658 (10.5) |
| History of COPD, n (%) | 8745 (6.6) | 6293 (5.6) | 1806 (12.8) | 646 (10.4) |
| History of asthma, n (%) | 14 531 (11.0) | 10 648 (9.5) | 2828 (20.0) | 1055 (16.9) |
| History of hypertension, n (%) | 36 134 (27.3) | 27 699 (24.8) | 6288 (44.4) | 2147 (34.4) |
| History of chronic kidney disease, n (%) | 9046 (6.8) | 6947 (6.2) | 1570 (11.1) | 529 (8.5) |
| Charlson Comorbidity Index, n (%) | ||||
| 0 | 78 981 (59.7) | 70 954 (63.4) | 5150 (36.4) | 2877 (46.1) |
| 1 | 13 828 (10.5) | 11 042 (9.9) | 1890 (13.3) | 896 (14.4) |
| ≥2 | 39 507 (29.9) | 29 945 (26.7) | 7123 (50.3) | 2469 (39.6) |
| Current use of medication, n (%) | ||||
| Systemic steroid | 38 237 (28.9) | 30 270 (27.1) | 5762 (40.7) | 2205 (35.3) |
| Metformin | 10 158 (7.7) | 7672 (6.9) | 1879 (13.3) | 607 (9.7) |
| Aspirin | 8049 (6.1) | 5769 (5.2) | 1787 (12.6) | 493 (7.9) |
COPD, chronic obstructive pulmonary disease; PPI, proton pump inhibitor; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.