Table 1.
Characteristics of individuals who received COVID-19 diagnostic tests and those who tested positive, by health insurance type, in Korea
| Characteristics | Recipients of COVID-19 diagnostic tests (n=232,390) |
Confirmed cases of COVID-19 (n=8,515) |
||||
|---|---|---|---|---|---|---|
| NHI (n=218,070) | Medicaid (n=14,320) | NHI (n=7,777) | Medicaid (n=738) | p-value1 | ||
| Age (yr)2 | ||||||
| Mean±SD | 50.2±20.0 | 63.8±17.7 | <0.001 | 47.8±19.1 | 57.5±16.8 | <0.001 |
| 19-29 | 41,802 (19.2) | 840 (5.9) | <0.001 | 2,039 (26.2) | 79 (10.7) | <0.001 |
| 30-39 | 39,995 (18.3) | 541 (3.8) | 903 (11.6) | 17 (2.3) | ||
| 40-49 | 33,040 (15.2) | 1,355 (9.5) | 1,047 (13.5) | 87 (11.8) | ||
| 50-59 | 30,600 (14.0) | 2,638 (18.4) | 1,536 (19.8) | 195 (26.4) | ||
| 60-69 | 26,631 (12.2) | 3,156 (22.0) | 1,139 (14.6) | 195 (26.4) | ||
| 70-79 | 22,949 (10.5) | 2,721 (19.0) | 650 (8.4) | 104 (14.1) | ||
| 80-89 | 19,257 (8.8) | 2,389 (16.7) | 391 (5.0) | 48 (6.5) | ||
| >89 | 3,796 (1.7) | 680 (4.7) | 72 (0.9) | 13 (1.8) | ||
| Sex2 | <0.001 | <0.001 | ||||
| Male | 102,964 (47.2) | 7,379 (51.5) | 3,127 (40.2) | 348 (47.2) | ||
| Female | 115,106 (52.8) | 6,941 (48.5) | 4,650 (59.8) | 390 (52.8) | ||
| Charlson comorbidity index score3 | ||||||
| Mean±SD | 2.2±1.7 | 2.4±1.6 | <0.001 | 1.7±1.0 | 2.0±1.1 | <0.001 |
| 1 | 37,850 (17.4) | 3,227 (22.5) | <0.001 | 1,229 (15.8) | 91 (12.3) | <0.001 |
| 2 | 29,667 (13.6) | 3,305 (23.1) | 862 (11.1) | 165 (22.4) | ||
| ≥3 | 24,905 (11.4) | 3,802 (26.6) | 387 (5.0) | 65 (8.8) | ||
| Comorbidities3 | ||||||
| Hypertension | 48,930 (22.4) | 5,999 (41.9) | <0.001 | 1,372 (17.6) | 208 (28.2) | <0.001 |
| Hyperlipidemia | 38,384 (17.6) | 3,852 (26.9) | <0.001 | 1,224 (15.7) | 183 (24.8) | <0.001 |
| Diabetes mellitus | 29,495 (13.5) | 4,470 (31.2) | <0.001 | 777 (10.0) | 145 (19.6) | <0.001 |
| Asthma | 15,375 (7.1) | 1,761 (12.3) | <0.001 | 383 (4.9) | 33 (4.5) | 0.585 |
| COPD | 37,010 (17.0) | 3,694 (25.8) | <0.001 | 1,021 (13.1) | 84 (11.4) | 0.177 |
| Atherosclerosis | 2,161 (1.0) | 331 (2.3) | <0.001 | 31 (0.4) | 11 (1.5) | <0.001 |
| Heart failure | 5,282 (2.4) | 942 (6.6) | <0.001 | 84 (1.1) | 17 (2.3) | 0.003 |
| Stroke | 9,384 (4.3) | 1,741 (12.2) | <0.001 | 198 (2.5) | 61 (8.3) | <0.001 |
| Myocardial infarction | 1,565 (0.7) | 262 (1.8) | <0.001 | 32 (0.4) | 6 (0.8) | 0.118 |
| Renal failure | 8,091 (3.7) | 1,792 (12.5) | <0.001 | 56 (0.7) | 17 (2.3) | <0.001 |
| Chronic liver disease | 16,894 (7.7) | 2,175 (15.2) | <0.001 | 457 (5.9) | 83 (11.2) | <0.001 |
| Fracture | 14,394 (6.6) | 2,080 (14.5) | <0.001 | 344 (4.4) | 62 (8.4) | <0.001 |
| Osteoarthritis | 33,865 (15.5) | 4,131 (28.8) | <0.001 | 1,063 (13.7) | 159 (21.5) | <0.001 |
| Rheumatoid arthritis | 3,152 (1.4) | 315 (2.2) | <0.001 | 105 (1.4) | 9 (1.2) | 0.768 |
| Psychiatric disorders | 33,143 (15.2) | 6,133 (42.8) | <0.001 | 857 (11.0) | 386 (52.3) | <0.001 |
| Thyroid disorders | 11,993 (5.5) | 1,067 (7.5) | <0.001 | 389 (5.0) | 52 (7.0) | 0.017 |
| Osteoporosis | 11,052 (5.1) | 1,533 (10.7) | <0.001 | 413 (5.3) | 54 (7.3) | 0.022 |
| Dementia | 11,885 (5.5) | 2,253 (15.7) | <0.001 | 315 (4.1) | 77 (10.4) | <0.001 |
| Cancer | 21,039 (9.6) | 1,834 (12.8) | <0.001 | 253 (3.3) | 31 (4.2) | 0.171 |
| Severe incurable disease4 | 37,628 (17.3) | 4,429 (30.9) | <0.001 | 495 (6.4) | 60 (8.1) | 0.063 |
| Concomitant medications3 | ||||||
| ACE inhibitors | 2,427 (1.1) | 396 (2.8) | <0.001 | 68 (0.9) | 12 (1.6) | 0.043 |
| ARBs | 40,853 (18.7) | 5,341 (37.3) | <0.001 | 1,096 (14.1) | 172 (23.3) | <0.001 |
| β-blockers | 28,367 (13.0) | 4,272 (29.8) | <0.001 | 667 (8.6) | 171 (23.2) | <0.001 |
| Calcium channel blockers | 40,060 (18.4) | 5,652 (39.5) | <0.001 | 943 (12.1) | 173 (23.4) | <0.001 |
| Diuretics | 14,107 (6.5) | 1,734 (12.1) | <0.001 | 429 (5.5) | 49 (6.6) | 0.205 |
| Nitrates | 8,932 (4.1) | 1,469 (10.3) | <0.001 | 103 (1.3) | 20 (2.7) | 0.003 |
| Antidiabetic drugs | 28,926 (13.3) | 4,401 (30.7) | <0.001 | 729 (9.4) | 149 (20.2) | <0.001 |
| Anxiolytics | 127,676 (58.5) | 12,052 (84.2) | <0.001 | 3,186 (41.0) | 544 (73.7) | <0.001 |
| Antipsychotics | 16,336 (7.5) | 4,494 (31.4) | <0.001 | 316 (4.1) | 292 (39.6) | <0.001 |
| Antidepressants | 30,304 (13.9) | 5,289 (36.9) | <0.001 | 721 (9.3) | 231 (31.3) | <0.001 |
| NSAIDs | 177,366 (81.3) | 11,814 (82.5) | <0.001 | 6,101 (78.4) | 527 (71.4) | <0.001 |
| Anticoagulants | 53,794 (24.7) | 7,739 (54.0) | <0.001 | 1,149 (14.8) | 231 (31.3) | <0.001 |
Values are presented as number (%).
COVID-19, coronavirus disease 2019; NHI, National Health Insurance; SD, standard deviation; COPD, chronic obstructive pulmonary disease; ACE, angiotensin converting enzyme; ARB, angiotensin-receptor II blocker; NSAID, non-steroidal anti-inflammatory drug.
The chi-square test for categorical variables and the t-test for continuous variables were used to determine statistically significant differences between health insurance types.
Assessed on cohort entry (the date when subjects received the test for COVID-19 or the date when subjects tested positive for COVID-19).
Assessed in the year prior to cohort entry.
Severe incurable diseases are Medicaid eligibility criteria, which include rare or incurable diseases.