Table 1 Baseline characteristics of the study population (n = 713,201).
| Characteristics | Control (n = 660,126) | Periodontitis (n = 53,075) | P value |
|---|---|---|---|
| Age, years | 31 (15-46) | 49 (39-60) | <0.0001 |
| CCI score | 0 (0-1) | 1 (0-2) | <0.0001 |
| Sex (%) | <0.0001 | ||
| Male | 325,796 (49.6) | 27,310 (51.5) | |
| Female | 334,330 (50.4) | 25,765 (48.5) | |
| BMI, kg/m2 | <0.0001 | ||
| < 20 | 89,951 (13.6) | 2,172 (4.1) | |
| 20 ~ 25 | 80,501 (12.2) | 13,088 (24.7) | |
| ≥ 25 | 41,969 (6.4) | 7,534 (14.2) | |
| Missing | 519,496 (78.7) | 30,281 (57.1) | |
| Smoking | <0.0001 | ||
| None | 89,951 (13.6) | 14,300 (26.9) | |
| Former | 12,049 (1.8) | 2,444 (4.6) | |
| Current | 36,498 (5.5) | 5,732 (10.8) | |
| Missing | 521,628 (79.0) | 30,599 (57.7) | |
| Level of income | <0.0001 | ||
| ≤ 50% (lower income) | 256,969 (39.5) | 18,910 (35.8) | |
| 51~80% | 226,055 (34.8) | 17,244 (32.6) | |
| ≥ 81% (higher income) | 166,857 (25.7) | 16,748 (31.7) | |
| Residential area | <0.0001 | ||
| Capital city | 133,337 (20.2) | 11,610 (21.9) | |
| Urban area | 171,117 (25.9) | 14,350 (27.0) | |
| Rural area | 255,672 (53.9) | 27,115 (51.1) |