Table 1. Baseline characteristics of the population included in the National Health Insurance Service–Health Examinee Cohort according to their experience of tooth loss.
| Variables | Number of teeth lost (No., %) | P value | ||||||
|---|---|---|---|---|---|---|---|---|
| Total | 0 | 1 | 2–3 | ≥4 | ||||
| Sex | <0.001 | |||||||
| Male | 136,658 (58.3) | 62,339 (45.7) | 23,817 (17.4) | 23,777 (17.4) | 26,665 (19.5) | |||
| Female | 97,589 (41.7) | 52,370 (53,7) | 16,866 (17.3) | 14,700 (15.1) | 13,653 (14.0) | |||
| Age group (yr) | <0.001 | |||||||
| 40–49 | 111,096 (47.4) | 64,266 (57.8) | 19,400 (17.5) | 15,207 (13.7) | 12,223 (11.0) | |||
| 50–59 | 68,651 (29.3) | 29,597 (43.1) | 12,849 (18.7) | 12,750 (18.6) | 13,455 (19.6) | |||
| 60–69 | 40,994 (17.5) | 14,898 (36.3) | 6,780 (16.5) | 8,237 (20.1) | 11,079 (27.0) | |||
| 70–79 | 13,506 (5.8) | 6,008 (44.5) | 1,654 (12.2) | 2,283 (16.9) | 3,561 (26.4) | |||
| Household incomea) | <0.001 | |||||||
| First quintile | 33,897 (14.5) | 15,824 (46.7) | 5,778 (17.0) | 5,756 (17.0) | 6,539 (19.3) | |||
| Second quintile | 29,908 (12.8) | 14,025 (46.9) | 5,102 (17.1) | 5,040 (16.9) | 5,741 (19.2) | |||
| Third quintile | 34,032 (14.5) | 15,743 (46.3) | 5,923 (17.4) | 5,857 (17.2) | 6,509 (19.1) | |||
| Fourth quintile | 48,118 (20.5) | 23,242 (48.3) | 8,398 (17.5) | 7,895 (16.4) | 8,583 (17.8) | |||
| Fifth quintile | 88,292 (37.7) | 45,935 (52.0) | 15,482 (17.5) | 13,929 (15.8) | 12,946 (14.7) | |||
| Insurance status | <0.001 | |||||||
| NHIS (Employees) | 161,841 (69.1) | 80,499 (49.7) | 28,385 (17.5) | 26,281 (16.2) | 26,676 (16.5) | |||
| NHIS (Self-employed) | 72,406 (30.9) | 34,270 (47.3) | 12,298 (17.0) | 12,196 (16.8) | 13,642 (18.8) | |||
| Presence of disabilityb) | <0.001 | |||||||
| None | 232,999 (99.5) | 114,213 (49.0) | 40,508 (17.4) | 38,254 (16.4) | 40,024 (17.2) | |||
| Present | 1,248 (0.5) | 556 (44.6) | 175 (14.0) | 223 (17.9) | 294 (23.6) | |||
| BMI (kg/m2) | <0.001 | |||||||
| <18.5 (Underweight) | 5,466 (2.3) | 2,860 (53.3) | 767 (14.3) | 724 (13.5) | 1,015 (18.9) | |||
| 18.5–23 (Normal) | 83,591 (35.7) | 43,845 (52.5) | 13,671 (16.4) | 12,515 (15.0) | 13,560 (16.2) | |||
| 23–25 (Overweight) | 64,655 (27.6) | 31,724 (49.1) | 11,489 (17.8) | 10,637 (16.5) | 10,805 (16.7) | |||
| ≥25 (Obese) | 80,635 (34.4) | 36,340 (45.1) | 14,756 (18.3) | 14,601 (18.1) | 14,938 (18.5) | |||
| Smoking status | <0.001 | |||||||
| Non/former smoker | 152,751 (65.2) | 80,427 (52.7) | 26,552 (17.4) | 23,513 (15.4) | 22,259 (14.6) | |||
| Current smoker | 81,496 (34.8) | 34,342 (42.1) | 14,131 (17.3) | 14,964 (18.4) | 18,059 (22.2) | |||
| Drinking status | <0.001 | |||||||
| None | 127,438 (54.4) | 64,315 (50.5) | 21,723 (17.0) | 20,212 (15.9) | 21,188 (16.6) | |||
| <3 times/wk | 81,101 (34.6) | 39,574 (48.8) | 14,582 (18.0) | 13,489 (16.6) | 13,456 (16.6) | |||
| ≥3 times/wk | 25,708 (11.0) | 10,880 (42.3) | 4,378 (17.0) | 4,776 (18.6) | 5,674 (22.1) | |||
| Periodic dental visits | <0.001 | |||||||
| Yes | 99,381 (42.4) | 43,269 (43.5) | 18,028 (18.1) | 18,085 (18.2) | 19,999 (20.1) | |||
| No | 134,866 (57.6) | 71,500 (53.0) | 22,655 (16.8) | 20,392 (15.1) | 20,319 (15.1) | |||
| Periodic scaling | <0.001 | |||||||
| Yes | 54,606 (23.3) | 25,569 (46.8) | 9,747 (17.8) | 9,515 (17.4) | 9,775 (17.9) | |||
| No | 179,641 (76.6) | 89,200 (49.7) | 30,936 (17.2) | 28,962 (16.1) | 30,543 (17.0) | |||
| Brushing before sleep | <0.001 | |||||||
| Yes | 69,599 (29.7) | 35,537 (51.1) | 12,257 (17.6) | 11,070 (15.9) | 10,735 (15.4) | |||
| No | 164,648 (70.3) | 79,232 (48.1) | 28,426 (17.3) | 27,407 (16.6) | 29,583 (18.0) | |||
| Comorbid disease | ||||||||
| Hypertension | 37,553 (16.0) | 16,357 (43.6) | 6,660 (17.7) | 6,855 (18.3) | 7,681 (20.5) | <0.001 | ||
| Diabetes mellitus | 14,191 (6.1) | 5,359 (37.8) | 2,288 (16.1) | 2,731 (19.2) | 3,813 (26.9) | <0.001 | ||
| CCI score | <0.001 | |||||||
| 0 | 152,388 (65.1) | 75,430 (49.5) | 26,479 (17.4) | 24,833 (16.3) | 25,646 (16.8) | |||
| 1 | 56,584 (24.2) | 27,368 (48.4) | 9,924 (17.5) | 9,394 (16.6) | 9,898 (17.5) | |||
| ≥2 | 25,275 (10.8) | 11,971 (47.4) | 4,280 (16.9) | 4,250 (16.8) | 4,774 (18.9) | |||
NHIS: National Health Insurance Service, CCI: Charlson comorbidity index, BMI: body mass index.
Boldface denotes statistical significance (P<0.05).
a)Divided into 5 quintiles based on the insurance fee imposed on each household; b)Classified by the Handicapped Welfare Law in South Korea.