Association between academic ability at age 11 and substance use across adolescence (risk ratios and 95% CIs, weighted for survey design)
| N=6059 | Onset of substance use in early adolescence (age 13–17) | Persistence of substance use in later adolescence (age 18–20) | ||||||
|---|---|---|---|---|---|---|---|---|
| Occasional cigarette smoking* | Persistent cigarette smoking* | Occasional cigarette smoking | Persistent cigarette smoking | |||||
| Academic ability | Minimally adjusted† | Additionally adjusted‡ | Minimally adjusted† | Additionally adjusted‡ | Minimally adjusted† | Additionally adjusted‡ | Minimally adjusted† | Additionally adjusted‡ |
| Medium (vs low) | 0.95 (0.74 to 1.23)§ | 0.96 (0.74 to 1.24)§ | 0.88 (0.69 to 1.11)§ | 0.89 (0.70 to 1.14)§ | ||||
| High (vs low) | 0.90 (0.71 to 1.14)§ | 0.96 (0.74 to 1.23)§ | 0.58 (0.45 to 0.74) | 0.62 (0.48 to 0.81) | ||||
| Occasional regular alcohol use¶ | Persistent regular alcohol use¶ | Occasional regular alcohol use* | Persistent regular alcohol use** | |||||
| Medium (vs low) | 1.58 (1.35 to 1.85) | 1.39 (1.17 to 1.64) | 2.07 (1.73 to 2.49) | 1.82 (1.50 to 2.21) | 0.85 (0.65 to 1.10)§ | 0.78 (0.59 to 1.02)§ | 1.92 (1.60 to 2.32) | 1.56 (1.27 to 1.92) |
| High (vs low) | 1.53 (1.30 to 1.81) | 1.25 (1.04 to 1.51) | 2.24 (1.87 to 2.67) | 1.83 (1.50 to 2.23) | 0.94 (0.72 to 1.23)§ | 0.89 (0.66 to 1.20)§ | 3.03 (2.51 to 3.65) | 2.28 (1.84 to 2.82) |
| Occasional cannabis use¶ | Persistent cannabis use¶ | Occasional cannabis use** | Persistent cannabis use** | |||||
| Medium (vs low) | 1.29 (1.09 to 1.53) | 1.25 (1.05 to 1.49) | 1.60 (1.30 to 1.98) | 1.53 (1.24 to 1.90) | 1.48 (1.24 to 1.77) | 1.37 (1.14 to 1.64) | 1.98 (1.62 to 2.43) | 1.81 (1.48 to 2.22) |
| High (vs low) | 1.12 (0.94 to 1.32)§ | 1.08 (0.90 to 1.29)§ | 1.32 (1.07 to 1.63) | 1.22 (0.98 to 1.52)§ | 1.70 (1.41 to 2.05) | 1.50 (1.22 to 1.83) | 2.34 (1.93 to 2.84) | 1.91 (1.57 to 2.34) |
*Represents substance use data at age 14/15 (2005) to 15/16 (2006).
†Adjusted for age and sex.
‡Additionally adjusted for longstanding disability/illness/infirmity, ethnic group, parental occupational social class and parental education.
§Represents significance level: p>0.05.
¶Represents substance use data at age 14/15 (2005) to 16/17 (2007).
**Represents substance use data at age 18/19 (2009) to 19/20 (2010).