Table 1. Baseline characteristics of the 23,770 eligible subjects.
| Total subjects (No) |
H. pylori seropositive subjects (No, [%]) |
||
|---|---|---|---|
| All | 23,770 | 9,871 [41.5] | |
| Gender | Male | 12,972 | 5,610 [43.2] |
| Female | 10,798 | 4,261 [39.5] | |
| Mean age±SD (years)† | 51.7±11.6 | 53.3±10.5 | |
| Age group (years) | 16–19 | 21 | 2 [9.5] |
| 20–29 | 763 | 112 [14.7] | |
| 30–39 | 2,726 | 830 [30.4] | |
| 40–49 | 6,326 | 2,567 [40.6] | |
| 50–59 | 8,115 | 3716 [45.8] | |
| 60–69 | 4,287 | 1972 [46.0] | |
| ≥70 | 1,532 | 672 [43.9] | |
| Geographical areas | Seoul | 14,270 | 5535 [38.8] |
| Gyeonggi | 4,258 | 1,729 [40.6] | |
| Chungcheong | 851 | 403 [47.4] | |
| Kyungsang | 2,760 | 1,354 [49.1] | |
| Cholla | 727 | 396 [54.5] | |
| Kangwon | 579 | 271 [46.8] | |
| Jeju | 325 | 183 [56.3] | |
| House income‡ | Low | 1,605 | 741 [46.2] |
| Medium | 9,157 | 3,901 [42.6] | |
| High | 11,589 | 4,650 [40.1] | |
| missing | 1,416 | 579 | |
| Educational level§ | Low | 1,027 | 516 [50.2] |
| Medium | 3,331 | 1,500 [45.0] | |
| High | 19,186 | 7,746 [40.4] | |
| missing | 226 | 109 |
Subjects with missing values were excluded; No, number; H. pylori, Helicobacter pylori; M, male; F, female; UGI, upper gastrointestinal
†mean ± standard deviation
‡Household income was classified as low (less than US $ 3,000 per month), medium (US $ 3,000 to 10,000 per month), or high (more than US $ 10,000 per month)
§Educational level was classified as low (middle school graduates or less), middle (high school graduates or university dropouts), or high (university graduates or graduates of a postgraduate course).