Table 1.
Baseline characteristics of the study population.
| Characteristics | Characteristics | Total (n = 5193) | Male (n = 1772) | Female (n = 3471) |
|---|---|---|---|---|
| Age, year (median, IQR) |
Age, year (median, IQR) | 55.1 (44.6 to 64.5) | 57.8 (43.2 to 66.7) | 53.8 (44.9 to 63.1) |
| 0 to 9 years | 157 (3.0%) | 107 (6.2%) | 50 (14.4%) | |
| 10 to 19 years | 110 (2.1%) | 67 (3.9%) | 43 (1.2%) | |
| 20 to 29 years | 219 (4.2%) | 91 (5.3%) | 128 (3.7%) | |
| 30 to 39 years | 424 (8.2%) | 110 (6.4%) | 314 (9.0%) | |
| 40 to 49 years | 968 (18.6%) | 212 (12.3%) | 756 (21.8%) | |
| 50 to 59 years | 1375 (26.5%) | 364 (21.1%) | 1011 (29.1%) | |
| 60 to 69 years | 1208 (23.3%) | 469 (27.2%) | 739 (21.3%) | |
| 70 to 79 years | 508 (9.8%) | 227 (13.2%) | 281 (8.1%) | |
| ≥80 years | 224 (4.3%) | 75 (4.4%) | 149 (4.3%) | |
| Ethnicity | Korean | 5111 (98.4%) | 1693 (33.1%) | 3418 (66.9%) |
| Non-Korean | 82 (1.6%) | 29 (35.4%) | 53 (64.6%) | |
| Medical institution |
Local clinics | 1792 (34.5%) | 693 (40.2%) | 1099 (31.7%) |
| Hospitals | 1959 (37.7%) | 515 (29.9%) | 1444 (41.6%) | |
| University hospitals | 625 (12.0%) | 312 (18.1%) | 313 (9.0%) | |
| Other referral clinical laboratories | 635 (12.2%) | 144 (8.4%) | 491 (14.1%) | |
| Public medical centers | 173 (3.%) | 49 (2.8%) | 124 (3.6%) | |
| Armed forced hospitals | 9 (0.2%) | 9 (0.5%) | 0 (0.0%) | |
| Geographic region |
Seoul and Gyeonggi-do | 3532 (68.8%) | 1157 (67.2%) | 2375 (68.4%) |
| Chungcheong province | 677 (13.0%) | 205(11.9%) | 472 (13.6%) | |
| Gyeongsang province | 590 (11.4%) | 169 (9.8%) | 421 (12.1%) | |
| Jeolla province | 384 (7.4%) | 185 (10.7%) | 199 (5.7%) | |
| Gangwon-do | 10 (0.2%) | 6 (0.3%) | 4 (0.1%) | |
| Jeju-do | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | |
| G6PD activity | G6PD, U/g Hb (median, IQR) | 11.6 (10.7 to 12.8) | 11.4 (10.5 to 12.6) | 11.7 (10.8 to 12.9) |
| G6PD, <7.9 U/g Hb (n, %) | 21 (0.4%) | 15 (0.9%) | 6 (0.2%) | |
| G6PD deficiency by WHO TSS |
<30% of the adjusted male median | 7 (0.4%) | 7 (0.4%) | 0 (0.0%) |
| Intermediate G6PD in female (30–80%) | 101 (2.9%) | Not applicable | 101 (2.9%) | |
| Possible G6PD variant classification |
Class A (<20%, chronic non-spherocytic hemolytic anemia) | 6 (0.1%) | 6 (0.3%) | 0 (0.0%) |
| Class B (<45%, acute hemolytic anemia) | 6 (0.1%) | 4 (0.2%) | 2 (0.1%) | |
| Class C (60–150%, no hemolysis) | 5003 (96.3%) | 1650 (95.8%) | 3353 (96.6%) | |
| Class U (others, uncertain clinical significance) | 178 (3.4%) | 62 (3.6%) | 116 (3.3%) |
Abbreviations: Hb—hemoglobin; IQR—interquartile range; G6PD—whole blood glucose-6-phosphatase dehydrogenase; WHO TSS—World Health Organization technical consultation series for evaluating diagnostic tests for G6PD activity. Intermediate classification is only applicable for females according to the WHO TSS for G6PD activity classification.