Table 2 Prevalence of use of legal and illegal substances in life, past year, and last month of the Thai population aged 18–65 between 2019 and 2021

Lifetime

Tobacco

2,081

41.6

42.1

42.09–42.12

20,772,536

1,786

33.1

33.5

33.47–33.49

14,982,175

1,623

28.6

28.9

28.87–28.90

12,878,374

13.1_{1.5, 35.2}

< 0.001***

Alcohol

3,263

65.2

65.6

65.62–65.65

32,378,450

3,000

55.7

56.0

55.95–55.98

25,045,434

2,729

48.1

48.3

48.26–48.29

21,523,662

12.8_{1.5, 37.1}

< 0.001***

Cannabis

496

9.9

10.1

10.10-10.11

4,984,683

334

6.2

6.2

6.24–6.25

2,794,914

361

6.4

6.4

6.40–6.42

2,857,484

9.2_{1.6, 39.0}

0.001**

Kratom leaves

303

6.1

6.20

6.19–6.20

3,057,364

267

5.0

4.9

4.89–4.90

2,190,528

729

12.9

12.8

12.81–12.83

5,718,039

14.4_{1.7, 39.8}

< 0.001***

Kratom cocktail

178

3.6

3.68

3.67–3.68

1,814,226

66

1.2

1.2

1.25–1.26

560,770

263

4.6

4.7

4.67–4.68

2,084,922

9.2_{1.4, 34.5}

< 0.001***

Methamphetamine

75

1.5

1.55

1.55–1.56

766,710

97

1.8

1.8

1.82–1.83

816,727

134

2.4

2.4

2.37–2.38

1,059,023

1.3_{1.8, 42.6}

0.269

Inhalants

10

0.2

0.22

0.22–0.22

110,251

15

0.3

0.3

0.28–0.28

124,388

16

0.3

0.3

0.28–0.29

127,322

0.1_{1.6, 37.9}

0.831

Others^c

13

0.3

0.29

0.29–0.29

143,218

12

0.2

0.2

0.22–0.22

98,572

16

0.3

0.3

0.29–0.29

127,980

0.4_{1.3, 30.5}

0.601

Past-year

Tobacco

1,401

28.0

28.5

28.53–28.56

14,081,141

1,233

22.9

23.2

23.14–23.17

10,362,083

1,244

21.9

22.1

22.09–22.12

9,857,004

5.7_{1.5, 36.4}

0.012*

Alcohol

2,526

50.5

51.0

51.02–51.05

25,175,616

2,170

40.3

40.6

40.59–40.62

18,169,572

2,080

36.7

36.8

36.75–36.78

16,392,140

15.2_{1.7, 39.9}

< 0.001***

Cannabis all routes

112

2.2

2.3

2.29–2.30

1,131,776

133

2.5

2.5

2.49–2.50

1,116,346

240

4.2

4.3

4.25–4.27

1,899,426

3.1_{1.9, 45.1}

0.058

 Smoking^d

60

53.6

51.8

51.68–51.86

615,968

68

51.1

51.2

51.19–51.38

572,511

64

26.7

26.6

26.57–26.69

505,787

4.3_{1.8, 44.1}

0.022*

 Oral use^d

67

59.8

59.5

59.44–59.61

708,204

63

47.4

47.2

47.08–47.27

526,609

147

61.3

61.2

61.13–61.26

1,162,359

0.9_{1.8, 44.1}

0.390

Kratom leaves

126

2.5

2.6

2.61–2.61

1,287,351

150

2.8

2.7

2.72–2.73

1,219,896

642

11.3

11.3

11.28–11.3

5,032,634

26.2_{1.7, 40.0}

< 0.001***

Kratom cocktail

40

0.8

0.9

0.87–0.88

431,041

35

0.6

0.7

0.66–0.67

296,546

199

3.5

3.6

3.55–3.56

1,585,543

22.4_{1.3, 30.5}

< 0.001***

Methamphetamine

4

0.1

0.1

0.08–0.09

41,756

29

0.5

0.5

0.55–0.55

247,252

7

0.1

0.1

0.13–0.13

57,109

12.9_{2.0, 47.0}

< 0.001***

Past-month

Tobacco

-

-

-

-

-

1,189

22.1

22.3

22.31–22.34

9,990,206

1,227

21.6

21.8

21.79–21.82

9,722,535

0.05_{1, 24}

0.826

Alcohol

-

-

-

-

-

2,043

37.9

38.2

38.2-38.23

17,103,039

1,800

31.8

31.8

31.83–31.86

14,200,474

8.1_{1, 24}

0.009**

Cannabis all routes

-

-

-

-

-

105

1.9

2.0

1.97–1.98

882,506

190

3.4

3.4

3.38–3.40

1,511,512

5.0_{1, 24}

0.035*

Kratom leaves

-

-

-

-

-

142

2.6

2.6

2.57–2.58

1,153,816

606

10.7

10.7

10.65–10.66

4,750,808

53.7_{1, 24}

< 0.001***

Kratom cocktail

-

-

-

-

-

31

0.6

0.6

0.58–0.59

262,382

184

3.2

3.3

3.29–3.30

1,467,382

71.3_{1, 24}

< 0.001***

Methamphetamine

-

-

-

-

-

18

0.3

0.3

0.34–0.35

154,055

6

0.1

0.1

0.11–0.11

49,166

4.9_{1, 24}

0.037*