Associations of cannabis use latent class membership with harmful behaviours at 21 years
| Unadjusted models | Adjusted models 1 | Adjusted models 2 | Adjusted models 3 | Adjusted models 4 | ||
|---|---|---|---|---|---|---|
| Reference class | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | OR (95% CI) | |
| Nicotine dependence | n=3215 | n=2772 | n=2197 | n=2134 | n=1863 | |
| Late-onset occasional | Non-user | 4.43 (1.82 to 10.8) | 3.68 (0.98 to 13.9) | 2.52 (0.38 to 16.9) | 2.58 (0.44 to 15.1) | 3.54 (0.70 to 17.9) |
| Early-onset occasional | Non-user | 5.78 (1.02 to 32.8) | 7.66 (0.78 to 74.9) | 13.5 (2.02 to 90.0) | 9.81 (1.25 to 76.6) | 12.1 (0.97 to 150.3) |
| Regular | Non-user | 26.7 (12.3 to 57.9) | 60.6 (22.8 to 161.3) | 51.1 (14.2 to 183.3) | 37.1 (11.0 to 125.2) | 37.2 (9.53 to 144.8) |
| Early-onset occasional | Late-onset occasional | 1.30 (0.20 to 8.48) | 2.08 (0.15 to 28.4) | 5.33 (0.38 to 74.6) | 3.80 (0.28 to 52.2) | 3.41 (0.18 to 66.2) |
| Regular | Late-onset occasional | 6.03 (2.30 to 15.8) | 16.5 (3.89 to 69.9) | 20.2 (2.19 to 186.7) | 14.4 (1.94 to 106.3) | 10.5 (1.42 to 77.7) |
| Regular | Early-onset occasional | 4.62 (0.72 to 29.7) | 7.92 (0.76 to 82.4) | 3.79 (0.54 to 26.71) | 3.78 (0.42 to 34.1) | 3.08 (0.24 to 40.1) |
| Harmful alcohol consumption | n=3046 | n=2631 | n=2093 | n=2034 | n=1772 | |
| Late-onset occasional | Non-user | 4.26 (2.96 to 6.13) | 3.93 (2.65 to 5.83) | 3.02 (1.90 to 4.82) | 3.09 (1.92 to 4.97) | 2.59 (1.54 to 4.34) |
| Early-onset occasional | Non-user | 8.18 (3.99 to 16.8) | 8.53 (4.09 to 17.8) | 7.34 (3.33 to 16.2) | 7.68 (3.47 to 17.0) | 5.03 (2.09 to 12.1) |
| Regular | Non-user | 3.45 (1.78 to 6.69) | 2.63 (1.23 to 5.64) | 2.67 (1.13 to 6.31) | 2.95 (1.22 to 7.11) | 2.61 (0.96 to 7.08) |
| Early-onset occasional | Late-onset occasional | 1.92 (0.87 to 4.24) | 2.17 (0.96 to 4.89) | 2.43 (1.00 to 5.91) | 2.48 (1.02 to 6.04) | 1.95 (0.73 to 5.19) |
| Regular | Late-onset occasional | 0.81 (0.39 to 1.70) | 0.67 (0.29 to 1.55) | 0.88 (0.34 to 2.27) | 0.95 (0.36 to 2.49) | 1.01 (0.34 to 2.98) |
| Regular | Early-onset occasional | 0.42 (0.16 to 1.15) | 0.31 (0.11 to 0.90) | 0.36 (0.11 to 1.16) | 0.38 (0.12 to 1.24) | 0.52 (0.14 to 1.86) |
| Other Illicit drug use | n=3048 | n=2631 | n=2094 | n=2033 | n=1772 | |
| Late-onset occasional | Non-user | 13.1 (8.79 to 19.4) | 13.8 (8.93 to 21.3) | 10.8 (6.59 to 17.7) | 11.3 (6.85 to 18.8) | 8.47 (4.99 to 14.4) |
| Early-onset occasional | Non-user | 8.26 (3.75 to 18.2) | 6.64 (2.59 to 17.0) | 3.34 (1.03 to 10.8) | 3.41 (1.06 to 10.92) | 3.21 (0.85 to 12.1) |
| Regular | Non-user | 27.0 (14.2 to 51.5) | 28.7 (13.55 to 60.6) | 25.6 (8.97 to 73.1) | 29.1 (8.49 to 100.0) | 25.9 (7.13 to 94.0) |
| Early-onset occasional | Late-onset occasional | 0.63 (0.27 to 1.48) | 0.48 (0.18 to 1.32) | 0.31 (0.09 to 1.07) | 0.30 (0.09 to 1.03) | 0.38 (0.09 to 1.51) |
| Regular | Late-onset occasional | 2.07 (1.02 to 4.21) | 2.08 (0.93 to 4.67) | 2.37 (0.74 to 7.53) | 2.57 (0.67 to 9.86) | 3.06 (0.77 to 12.1) |
| Regular | Early-onset occasional | 3.27 (1.17 to 9.14) | 4.31 (1.30 to 14.4) | 7.67 (1.55 to 37.9) | 8.55 (1.51 to 48.4) | 8.08 (1.26 to 51.6) |
Rates of harmful behaviours across class were as follows: non-cannabis users (1% nicotine dependence, 8.4% harmful alcohol consumption, 13.6% other illicit drug use); late-onset occasional cannabis users (4.3% nicotine dependence, 28.0% harmful alcohol consumption, 83.1% other illicit drug use); early-onset occasional cannabis users (5.5% nicotine dependence, 42.7% harmful alcohol consumption, 83.0% other illicit drug use); regular cannabis users (21.2% nicotine dependence, 23.9% harmful alcohol consumption, 94.3% other illicit drug use).
Reference categories for outcomes are: nicotine dependence ‘non-smoker/low/very low dependence’; alcohol consumption ‘low risk/hazardous’; other illicit drug use ‘never used/not used in last 3 months’.
Confounders adjusted for: (model 1) sex; household income, housing tenure; crowding status; birth order; maternal educational attainment; (model 2) additionally adjusted for maternal substance use (smoking, alcohol consumption and cannabis use); (model 3) additionally adjusted for child conduct problems at age 11 years; (model 4) additionally adjusted for tobacco and alcohol use at age 13 years.
All p values <0.001.