Table 3.
Proportion of participants who did and did not change past-year substance use from cycles 22 to 23 compared to cycles 23 to 24, Nicotine Dependence in Teens study, Montreal, Canada, 2017-21
| Cannabis % (95% CI) |
Alcohol % (95% CI) |
Binge drinking % (95% CI) |
Combustible cigarettes % (95% CI) |
E- cigarettes† % (95% CI) | |||||
|---|---|---|---|---|---|---|---|---|---|
| Cycle 22-23 | Cycle 23-24 | Cycle 22-23 | Cycle 23-24 | Cycle 22-23 | Cycle 23-24 | Cycle 22-23 | Cycle 23-24 | Cycle 23-24 | |
| Proportion of participants who did not change substance use* | |||||||||
| Overall (proportion of total sample) | 60.0 (57.5; 62.5) |
67.1 (64.9; 69.4) |
50.0 (47.4; 52.6) |
48.9 (46.5; 51.3) |
47.1 (44.6; 49.7) |
51.3 (48.8; 53.7) |
67.2 (64.8; 69.5) |
76.5 (74.4; 78.5) |
84.0 (82.2; 85.7) |
| Stable nonusers¥ (proportion of non- users) | 81.7 (78.9; 84.2) |
82.8 (80.4; 85.1) |
60.9 (51.6; 69.7) |
50.6 (43.7; 57.4) |
70.6 (65.7; 75.1) |
84.0 (80.8; 86.9) |
90.7 (88.6; 92.6) |
94.5 (93.07; 95.8) |
93.9 (92.6; 95.1) |
| Stable users‡ (proportion of users) | 33.5 (29.9; 37.2) |
39.2 (35.5; 43.0) |
51.3 (48.6; 53.9) |
48.2 (45.6; 50.8 |
39.4 (36.6; 42.4) |
35.9 (33.1; 38.8) |
36.9 (33.3; 40.7) |
38.7 (34.6; 42.9) |
8.7 (18.8; 18.5) |
| Stable weekly/daily users§ (proportion of users) | 18.6 (15.7; 21.7) |
25.1 (21.9; 28.6) |
31.6 (29.2; 34.2 |
34.4 (32.0; 36.9) |
6.2 (4.9;7.7) |
6.2 (4.9; 7.8) |
27.6 (24.3; 31.1) |
28.4 (24.7; 32.3) |
9.6 (5.9; 14.4) |
| Proportion of participants who changed substance use* | |||||||||
| Overall (proportion of total sample) | 40.0 (37.5; 42.5) |
32.9 (30.6; 35.1) |
50.0 (47.4; 52.5) |
51.1 (48.7; 53.5) |
52.9 (50.3; 55.4) |
48.7 (46.3; 51.2) |
32.8 (30.5; 35.2) |
23.5 (21.5; 35.6) |
16.0 (14.3; 17.8) |
| Initiated/increased£ (incidence among non- users and less than daily users) | 18.5 (16.4; 20.6) |
22.4 (20.4; 24.6) | 26.3 (24.1; 28.6) |
21.5 (19.5; 23.6) |
15.9 (14.1; 17.8) |
12.5 (10.9; 14.2) |
10.1 (8.4; 11.8) |
7.3 (6.0; 8.8) |
7.1 (5.9; 8.4) |
| Quit/decreased use¤ (incidence among users) | 49.6 (45.7; 53.5) |
35.4 (31.8; 39.1) |
23.0 (20.9; 25.3) |
35.2 (32.8; 37.7) |
47.5 (44.6; 50.4) |
53.5 (50.5; 56.5) |
54.7 (50.9; 58.5) |
53.2 (49.0; 57.4) |
72.5 (65.7; 78.6) |
Prevalence, incidence and 95% CI are weighted for non-response.
Note: Mean age of participants was 24.0, 30.6 and 33.6 years in cycle 22, 23 and 24, respectively.
Data on e-cigarette use are not available at cycle 22.
Proportion of nonusers in cycle t who remained non-user in cycle t+1.
Proportion of users in cycle t who reported the same frequency of use in cycle t+1.
Proportion of users in cycle t who reported daily/weekly use in cycles t and t+1.
Cumulative incidence of increased use in cycle t+1. The denominator corresponds to non-daily users in cycle t.
Cumulative incidence of decreased use in cycle t+1. The denominator corresponds to users in cycle t.