Table 1.
Demographic and clinical characteristics of the participants in the main cohort. a
| Total no. (%), (N = 1,537,066) a | Social economic status (SES, 0 to 4) | p value | |||||
|---|---|---|---|---|---|---|---|
| 0 (Medical aid) no. (%), (N = 35,292) a | 1 (Lowest) no. (%), (N = 181,756) a | 2 (Low to Middle) no. (%), (N = 241,103) a | 3 (Middle to High) no. (%), (N = 498,685) a | 4 (Highest) no. (%), (N = 580,230) a | |||
| 1. Baseline characteristics b | |||||||
| 1) Age, mean (yr) | 6.4 ± 4.3 | 9.0 ± 5.1 | 7.0 ± 4.6 | 6.1 ± 4.3 | 5.6 ± 3.8 | 6.7 ± 4.3 | |
| 2) Age group (n) | <0.0001 | ||||||
| ≥2, <6 year | 838,653 (54.6) | 11,768 (33.3) | 87,328 (48.0) | 139,491 (57.9) | 310,670 (62.3) | 289,396 (49.9) | |
| ≥6,<12 year | 483,054 (31.4) | 11,534 (32.7) | 61,069 (33.6) | 69,986 (29.0) | 140,882 (28.3) | 199,583 (34.4) | |
| ≥12, <19 year | 215,359 (14.0) | 11,990 (34.0) | 33,359 (18.4) | 31,626 (13.1) | 47,133 (9.5) | 91,251 (15.7) | |
| 3) Sex | <0.0001 | ||||||
| Male | 811,729 (52.8) | 17,935 (50.8) | 96,005 (52.8) | 126,603 (52.5) | 260,560 (52.2) | 310,626 (53.5) | |
| Female | 725,337 (47.2) | 17,357 (49.2) | 85,751 (47.2) | 114,500 (47.5) | 238,125 (47.8) | 269,604 (46.5) | |
| 4) Type of insurance | <0.0001 | ||||||
| Self-employed health insurance | 350,244 (22.8) | – | 38,368 (21.1) | 78,571 (32.6) | 122,164 (24.5) | 111,141 (19.2) | |
| Employed health insurance | 1,151,530 (74.9) | – | 143,388 (78.9) | 162,532 (67.4) | 376,521 (75.5) | 469,089 (80.8) | |
| Medical aid | 35,292 (2.3) | 35,292 (100.0) | – | – | – | – | |
| 5) Residence | <0.0001 | ||||||
| Seoul | 263,949 (17.2) | 4,516 (12.8) | 26,917 (14.8) | 37,395 (15.5) | 74,534 (14.9) | 120,587 (20.8) | |
| Metropolitan | 398,250 (25.9) | 11,363 (32.2) | 48,867 (26.9) | 63,561 (26.4) | 133,054 (26.7) | 141,405 (24.4) | |
| Urban | 791,801 (51.5) | 16,175 (45.8) | 92,235 (50.7) | 123,599 (51.3) | 262,586 (52.7) | 297,206 (51.2) | |
| Rural | 83,066 (5.4) | 3,238 (9.2) | 13,737 (7.6) | 16,548 (6.9) | 28,511 (5.7) | 21,032 (3.6) | |
| 2. Allergy history, except bronchial asthma b | |||||||
| 1) Allergic rhinitis | 1,160,865 (75.5) | 29,129 (82.5) | 140,836 (77.5) | 179,938 (74.6) | 362,233 (72.6) | 448,729 (77.3) | <0.0001 |
| 2) Atopic dermatitis | 525,733 (34.2) | 11,389 (32.3) | 61,659 (33.9) | 82,949 (34.4) | 174,547 (35.0) | 195,189 (33.6) | <0.0001 |
| 3. Asthma medications during follow-up b | |||||||
| 1) Any Intranasal corticosteroids (ICS) | 736,400 (47.9) | 15,399 (43.6) | 83,767 (46.1) | 116,504 (48.3) | 250,386 (50.2) | 270,344 (46.6) | <0.0001 |
| 2) Systemic corticosteroids | 662,826 (43.1) | 15,266 (43.3) | 78,022 (42.9) | 105,946 (43.9) | 219,088 (43.9) | 244,504 (42.1) | <0.0001 |
| 3) Leukotriene receptor antagonists (LTRA) | 877,807 (57.1) | 18,708 (53.0) | 100,840 (55.5) | 135,384 (56.2) | 287,951 (57.7) | 334,924 (57.7) | <0.0001 |
| 4) Long-acting beta-2 agonists (LABA) | 1,227,848 (79.9) | 25,169 (71.3) | 141,623 (77.9) | 196,028 (81.3) | 414,430 (83.1) | 450,598 (77.7) | <0.0001 |
| 5) Shot-acting beta-2 agonists (SABA) | 811,096 (52.8) | 17,613 (49.9) | 93,899 (51.7) | 129,370 (53.7) | 273,247 (54.8) | 296,967 (51.2) | <0.0001 |
| 6) Anticholinergics | 22,675 (1.5) | 906 (2.6) | 3,078 (1.7) | 3,718 (1.5) | 6,679 (1.3) | 8,294 (1.4) | <0.0001 |
| 7) Xanthines | 370,150 (24.1) | 10,158 (28.8) | 45,418 (25.0) | 60,526 (25.1) | 120,671 (24.2) | 133,377 (23.0) | <0.0001 |
| 8) Only LABA | 1,215,410 (79.1) | 24,466 (69.3) | 139,684 (76.9) | 194,204 (80.5) | 411,752 (82.6) | 445,304 (76.7) | <0.0001 |
a
Values are reported as n (%) unless otherwise indicated.
b
Obtained from Korean National Health Insurance Service (NHIS) data.