Table 2 Crude odds ratios and 95% confidence intervals of the variables associated with having < 20 teeth

Age

80–84

Reference

Reference

85–89

1.323

0.981

1.783

0.066

1.622

1.177

2.236

0.003

90–94

2.574

1.901

3.485

 < 0.001

2.619

1.866

3.676

 < 0.001

95–99

4.119

2.664

6.367

 < 0.001

4.602

2.852

7.426

 < 0.001

≥100

6.013

3.570

10.13

 < 0.001

8.066

5.278

12.32

 < 0.001

Household income per capita

Q1

Reference

Reference

Q2

0.770

0.461

1.287

0.319

1.110

0.687

1.794

0.671

Q3

0.499

0.306

0.812

0.005

0.846

0.540

1.325

0.464

Q4

0.423

0.268

0.667

 < 0.001

0.745

0.475

1.167

0.198

Q5

0.346

0.220

0.542

 < 0.001

0.545

0.355

0.839

0.006

Current residence area

Rural (Ref. Urban)

1.878

1.386

2.545

 < 0.001

1.236

0.918

1.663

0.163

Marital status

Unmarried (Ref. Married)

1.402

1.053

1.866

0.021

1.417

1.029

1.950

0.033

Illiterate

Yes (Ref. No)

1.591

1.149

2.203

0.005

1.685

1.244

2.283

 < 0.001

Brushing less than once per day^a

Yes (Ref. No)

2.347

1.656

3.324

 < 0.001

2.276

1.538

3.367

 < 0.001

Green tea consumption

Less than once per month

Reference

Reference

Some of the time

1.222

0.500

2.984

0.660

0.586

0.211

1.63

0.306

Almost everyday

0.574

0.388

0.849

0.005

0.661

0.376

1.164

0.152

Mushroom consumption

Less than once per month

Reference

Reference

Some of the time

0.657

0.491

0.880

0.005

0.814

0.598

1.109

0.192

Almost everyday

0.614

0.276

1.368

0.233

0.704

0.303

1.635

0.414

Fish consumption

Less than once per month

Reference

Reference

Some of the time

0.583

0.427

0.796

0.001

0.752

0.552

1.024

0.070

Almost everyday

0.454

0.273

0.756

0.002

0.933

0.550

1.583

0.796

Milk consumption

Less than once per month

Reference

Reference

Some of the time

0.598

0.422

0.846

0.004

0.899

0.626

1.292

0.566

Almost everyday

0.423

0.294

0.609

 < 0.001

0.635

0.428

0.942

0.024

Sugar consumption

Less than once per month

Reference

Reference

Some of the time

1.108

0.812

1.512

0.516

1.537

1.088

2.171

0.015

Almost everyday

0.555

0.348

0.883

0.013

1.230

0.734

2.061

0.432

Alcohol consumption

Never drink

Reference

Reference

Drank in the past

1.123

0.699

1.805

0.630

0.604

0.213

1.71

0.342

Drink at present

1.028

0.641

1.648

0.909

1.182

0.322

4.339

0.801

Cigarette smoking

Never smoked

Reference

Reference

Previous smoker

1.153

0.837

1.587

0.383

1.488

0.716

3.094

0.287

Current smoker

1.925

1.324

2.800

 < 0.001

1.089

0.566

2.093

0.799

ADL capacity

Disabled (Ref. Not disabled)

1.881

1.219

2.903

0.004

1.933

1.278

2.924

0.002

Hypertension

Yes (Ref. No)

0.712

0.531

0.955

0.024

0.850

0.628

1.151

0.293

Diabetes

Yes (Ref. No)

0.598

0.400

0.896

0.013

0.655

0.441

0.973

0.036

Overweight (BMI ≥ 25)

Yes (Ref. No)

0.690

0.493

0.968

0.031

0.802

0.572

1.123

0.199