Table 1 Past 12-month prevalence of cannabis use frequency, route of administration, and co-use with alcohol across gender by age subgroups, 2014–2016 Washington state general population (N = 5429)

P for difference across ages

18–29

30–49

50–64

≥65

(n=330)

(n=753)

(n=947)

(n=1037)

Never used cannabis in past the 12 months (%)

62.2

75.1

76.5

91.5

< 0.001

n of past 12-month cannabis users

111

174

200

97

 Infrequent^a

28.0

32.7

27.0

46.8

0.36

 Regular

38.9

33.5

38.6

35.3

 Daily/near daily

33.0

33.8

34.4

17.9

 Smoke only

73.9

73.2

64.9

58.7

0.54

 Vaporize

4.9

8.6

8.9

11.2

 Edibles, drinks, oral

15.6

14.1

17.6

25.9

 Other

5.7

4.0

8.5

4.1

 Cannabis only/no alcohol

9.2

14.3

24.5

13.3

0.06

 Always uses separately

42.2

41.8

36.2

51.6

 Usually/always

48.6

43.9

39.3

35.1

P for difference

18–29

30–49

50–64

≥65

(n=349)

(n=624)

(n=747)

(n=705)

across ages

Never used cannabis in past the 12 months (%)

52.3

67.3

70.3

83.8

< 0.001

n of past 12-month cannabis users

153

176

196

93

 Infrequent

19.8

24.3

20.7

23.2

0.23

 Regular

41.5

26.7

40.2

34.9

 Daily/near daily

38.6

49.1

39.2

41.9

 Smoke only

79.4

74.6

79.1

56.6

0.008

 Vaporize

10.4

11.9

6.2

12.9

 Edibles, drinks, oral

6.6

5.9

12.6

21.5

 Other

3.7

7.6

2.1

9.0

 Cannabis only/no alcohol

9.2

16.2

22.5

25.7

0.13

 Always uses separately

32.6

27.8

26.7

32.8

 Usually/always

58.2

56.0

50.8

41.5