Table 1. Demographic Characteristics of Participating Adolescents in the Korea Youth Risk Behavior Web-based Survey, 2005-2021.
| Variable | Weighted sample | |||||
|---|---|---|---|---|---|---|
| Overall | 2005-2007 | 2008-2011 | 2012-2015 | 2016-2019 | COVID-19 pandemic (2020-2021) | |
| Estimated weighted sample size, mean (SD) | 56 122 639 (226 267) | 10 518 980 (109 115) | 15 148 697 (126 299) | 13 901 009 (89 830) | 11 418 859 (89 830) | 5 135 095 (58 931) |
| Proportion (95% CI) | 100.0 (100.0-100.0) | 18.7 (18.4-19.1) | 27.0 (26.6-27.4) | 24.8 (24.4-25.1) | 20.3 (20.1-20.6) | 9.1 (9.0-9.4) |
| Age, mean (95% CI), y | 15.04 (15.03-15.05) | 14.88 (14.85-14.91) | 15.08 (15.06-15.11) | 14.99 (14.97-15.01) | 15.12 (15.09-15.14) | 15.20 (15.17-15.24) |
| School grade, proportion (95% CI) | ||||||
| 7-9 (Middle school) | 50.3 (49.9-50.6) | 56.3 (55.3-57.2) | 50.6 (49.8-51.4) | 48.4 (47.7-49.2) | 46.4 (45.6-47.2) | 50.4 (49.3-51.6) |
| 10-12 (High school) | 49.7 (49.4-50.1) | 43.7 (42.8-44.7) | 49.4 (48.6-50.2) | 51.6 (50.8-52.3) | 53.6 (52.8-54.4) | 49.6 (48.4-50.7) |
| Sex, proportion (95% CI) | ||||||
| Male | 52.4 (51.8-53.1) | 52.9 (51.2-54.6) | 52.8 (51.4-54.2) | 52.3 (50.9-53.7) | 52.1 (50.7-53.4) | 51.9 (50.2-53.6) |
| Female | 47.6 (46.9-48.2) | 47.1 (45.4-48.8) | 47.7 (45.8-48.6) | 47.7 (46.3-49.1) | 47.9 (46.6-49.3) | 48.1 (46.4-49.8) |
| BMI, mean (95% CI) | 20.79 (20.78-20.81) | 20.48 (20.45-20.51) | 20.48 (20.45-20.50) | 20.73 (20.70-20.75) | 21.25 (21.22-21.27) | 21.55 (21.51-21.60) |
| Residence, proportion (95% CI) | ||||||
| Rural | 45.9 (45.5-46.3) | 47.3 (46.3-48.3) | 50.1 (49.3-51.0) | 44.0 (43.3-44.7) | 43.0 (42.3-43.8) | 42.2 (41.1-43.2) |
| Urban | 54.1 (53.7-54.5) | 52.7 (51.7-53.7) | 49.9 (49.0-50.7) | 56.0 (55.3-56.7) | 57.0 (56.2-57.7) | 57.8 (56.8-58.9) |
| Smoking, proportion (95% CI) | 9.5 (9.4-9.7) | 12.3 (11.9-12.6) | 12.2 (11.9-12.5) | 9.3 (9.0-9.6) | 6.2 (6.0-6.4) | 4.3 (4.1-4.5) |
| Current alcohol use, proportion (95% CI) | 19.3 (19.2-19.5) | 27.6 (27.2-28.1) | 21.6 (12.2-21.9) | 17.0 (16.7-17.3) | 15.4 (15.1-15.7) | 10.5 (10.2-10.8) |
| Sadness, proportion (95% CI) | 31.5 (31.3-31.6) | 37.8 (37.4-38.2) | 36.4 (36.1-36.7) | 27.8 (27.5-28.1) | 26.1 (25.9-26.4) | 25.8 (25.4-26.2) |
| Suicidality, proportion (95% CI) | 16.6 (16.5-16.7) | 23.0 (22.7-23.3) | 18.9 (18.7-19.2) | 14.7 (14.5-14.9) | 12.3 (12.1-12.5) | 11.6 (11.3-11.9) |
| Suicide attempt, proportion | 3.6 (3.6-3.7) | 5.1 (5.0-5.3) | 4.4 (4.3-4.5) | 3.2 (3.1-3.3) | 2.5 (2.4-2.6) | 2.0 (1.9-2.1) |
| Highest educational level of parents, proportion (95% CI) | ||||||
| High school or lower | 46.4 (46.1-46.7) | 62.7 (62.0-63.4) | 55.6 (55.1-56.2) | 45.4 (45.0-45.9) | 31.7 (31.2-32.1) | 21.1 (20.6-21.7) |
| College or higher | 38.5 (38.2-38.8) | 27.2 (26.5-28.0) | 33.9 (33.3-34.5) | 42.1 (41.5-42.6) | 47.8 (47.2-48.4) | 44.9 (44.2-45.6) |
| Unknown | 15.1 (15.0-15.2) | 10.1 (9.8-10.3) | 10.4 (10.2-10.7) | 12.5 (12.3-12.7) | 20.5 (20.2-20.9) | 34.0 (33.4-34.5) |
| Economic level, proportion (95% CI) | ||||||
| High | 8.1 (8.0-8.2) | 7.3 (7.1-7.5) | 6.3 (6.1-6.5) | 7.6 (7.4-7.8) | 10.4 (10.2-10.7) | 11.0 (10.7-11.3) |
| Middle-high | 27.0 (26.8-27.2) | 31.2 (30.7-31.6) | 23.2 (22.9-23.5) | 25.6 (25.3-25.9) | 29.0 (28.7-29.3) | 29.2 (28.7-29.6) |
| Middle | 46.7 (46.6-46.9) | 43.9 (43.5-44.3) | 47.2 (47.0-47.5) | 47.6 (47.3-47.9) | 46.9 (46.6-47.3) | 48.3 (47.8-48.8) |
| Middle-low | 14.3 (14.2-14.5) | 14.0 (13.7-14.3) | 17.7 (17.5-18.0) | 15.3 (15.1-15.5) | 11.2 (11.1-11.4) | 9.6 (9.3-9.8) |
| Low | 3.8 (3.8-3.9) | 3.7 (3.6-3.8) | 5.6 (5.5-5.7) | 3.9 (3.9-4.1) | 2.3 (2.3-2.4) | 1.9 (1.8-2.0) |
| School performance, proportion (95% CI) | ||||||
| High | 12.2 (12.1-12.3) | 13.5 (13.3-13.8) | 11.3 (11.1-11.5) | 11.5 (11.3-11.7) | 13.1 (12.9-13.3) | 12.4 (12.1-12.7) |
| Middle-high | 25.5 (25.4-25.6) | 29.1 (28.8-29.3) | 24.0 (23.8-24.2) | 24.6 (24.4-24.7) | 25.5 (25.3-25.7) | 24.8 (24.4-25.1) |
| Middle | 28.5 (28.4-28.6) | 29.3 (29.0-29.6) | 27.2 (27.0-27.5) | 27.9 (27.7-28.1) | 29.4 (29.2-29.6) | 30.7 (30.4-31.0) |
| Middle-low | 23.4 (23.3-23.5) | 20.3 (20.1-20.6) | 25.6 (25.4-25.8) | 24.5 (24.3-24.7) | 22.3 (22.1-22.6) | 22.4 (22.1-22.7) |
| Low | 10.4 (10.3-10.5) | 7.8 (7.6-8.0) | 11.9 (11.7-12.0) | 11.6 (11.4-11.7) | 9.7 (9.5-9.8) | 9.7 (9.5-9.9) |
Abbreviation: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared).