Table 4 Univariable logistic regression analysis for periodontal disease

Age (years)

 40–49

1738 (28.8)

Ref

 50–59

 60–69

 70–79

 ≥ 80

3324 (39.7)

4798 (45.7)

3039 (42.7)

1446 (32.3)

1.63 (1.52–1.75)

2.08 (1.94–2.23)

1.84 (1.71–1.98)

1.18 (1.09–1.28)

< 0.001

< 0.001

< 0.001

< 0.001

Gender

 Male

7278 (42.1)

Ref

 Female

7067 (36.8)

0.80 (0.77–0.84)

< 0.001

BMI

 Healthy

10,218 (39.3)

Ref

 Underweight

 Overweight

 Obese

1054 (38.1)

2684 (40.0)

389 (38.6)

0.95 (0.88–1.03)

1.03 (0.98–1.09)

0.97 (0.85–1.11)

0.219

0.277

0.655

Living status

 With 5 persons or more

3776 (37.9)

Ref

 With 3–4 persons

 With 1–2 persons

 Alone

4371 (38.0)

5951 (41.2)

247 (43.8)

1.01 (0.95–1.06)

1.15 (1.09–1.21)

1.28 (1.08–1.52)

0.856

< 0.001

0.005

Smoking habit

 Never

7408 (39.5)

Ref

 Former smoker

 Current smoker

4146 (38.8)

2791 (39.5)

0.99 (0.94–1.05)

0.97 (0.92–1.02)

0.907

0.214

Drinking habit

 Never

4839 (38.4)

Ref

 Former drinker

 Current drinker

777 (42.1)

8729 (39.6)

1.05 (1.00–1.10)

1.17 (1.06–1.29)

0.034

0.002

Number of remaining teeth

 ≥ 20 teeth

7848 (35.8)

Ref

 10–19 teeth

 1–9 teeth

 No natural teeth

 Don’t know

2640 (49.8)

1695 (50.5)

700 (44.2)

1462 (33.9)

1.78 (1.67–1.89)

1.83 (1.70–1.97)

1.42 (1.28–1.58)

0.92 (0.86–1.28)

< 0.001

< 0.001

< 0.001

0.152

Bite availability on molars

 Both sides

10,660 (36.9)

Ref

 One side

 No side

2616 (47.5)

1069 (50.4)

1.54 (1.46–1.64)

1.74 (1.59–1.89)

< 0.001

< 0.001

History of dry eye diagnosis

 No

13,289 (39.1)

Ref

 Yes

1056 (42.0)

1.13 (1.04–1.22)

0.005

Feels dryness of eyes

 Never

9666 (38.9)

Ref

 Sometimes

 Always

4137 (40.1)

542 (41.2)

1.10 (0.99–1.23)

1.05 (1.00–1.10)

0.090

0.045

Feels a foreign body in the eyes

 Never

10,361 (39.3)

Ref

 Sometimes

 Always

3712 (39.0)

272 (45.0)

0.99 (0.94–1.04)

1.26 (1.07–1.49)

0.678

0.005