best practice

Life skills programmes were found in a systematic review (Faggiano et al., 2014) to have a more positive trend than usual curricula in:

• reducing use of hard drugs at >12 months follow-up (RR 0.69, 95 % CI 0.40 to 1.18, 1 study, N=2090)
• reducing use of hard drugs at 12+ months follow-up (MD -0.01, 95 % CI -0.06 to 0.04, 1 study, N=1075)

School programmes based on a combination of social competence (life skills-based) and social influence approaches were found in a systematic review (Faggiano et al., 2014) to have no different effect than usual school curricula or no intervention in:

• reducing hard drug use at <12 months follow-up (conflicting results between dichotomous and continuous outcomes within 1 study, N=693)
• reducing hard drug use at 12+ months follow-up (RR 0.86, 95 % CI 0.39 to 1.90, 2 studies, N=1066)

School programmes based on social competence approaches were found in a systematic review (Faggiano et al., 2014) to be more effective than usual curricula in:

• reducing use of cannabis at <12 months follow-up (RR 0.88, 95 % CI 0.72 to 1.07, 3 studies, N=10 716);
• reducing use of cannabis at 12+ months follow-up (RR 0.95, 95 % CI 0.81 to1.13, 1 study, N=5 862)
• reducing use of hard drugs  (just one study not providing data for meta-analysis found a significant protective effect)

Life skills programmes were found in a systematic review (Faggiano et al., 2014) to have a more positive trend than usual curricula in:

• reducing use of cannabis at <12 months follow-up (RR 0.90, 95 % CI 0.81 to 1.01, 4 studies, N=9456);
• reducing use of cannabis at 12+ months follow-up (RR 0.86, 95 % CI 0.74 to1.00, 1 study, N=2678)

School-based anti-bullying programmes were found in a systematic review with meta-analysis (Ng et al., 2020, 17 studies, N= 35 694 adolescents) to have very small to small yet significant effect in:

• reducing traditional bullying and cyberbullying perpetration (traditional:SMD -0.30 and cyber: SMD - 0.16)
• reducing traditional bullying and cyberbullying victimization (traditional: SMD - 0.18 and cyber: SMD - 0.13)

Type of intervention (i.e., whole school–based or classroom-based), program duration, and presence of parental involvement did not moderate program effectiveness, but cyberbullying programs were more effective when delivered by technology-savvy content experts compared to teachers.

The results of a second systematic review with meta-analysis (Fraguas, et al. 2020, 69 RCTs, N = 111 659) support the feasibility of implementing anti-bullying programs in schools and suggest their potential effectiveness. School anti-bullying interventions were found to have small but significant effect in:

• reducing bullying (ES - effect size -, −0.150; 95%CI, −0.191 to −0.109)
• improving mental health problems (ES, −0.205; 95%CI, −0.277 to −0.133) at study end point,
• with PINs -Population Impact Number - for universal interventions that target the total student population of 147 (95%CI, 113-213) and 107 (95%CI, 73-173), respectively. In other words, for an estimated bullying prevalence of 15% (a conservative estimate considering prevalence rates reported in previous studies), an average anti-bullying intervention needs to include 147 (95% CI, 113-213) people to prevent 1 case of bullying and 107 (95% CI, 73-173) people to improve mental health problems. We also found a substantial population impact (PIN, 167; 95%CI, 100-360) for interventions targeting cyberbullying (ie, 167 young people on average need to receive the intervention to prevent 1 case of cyberbullying perpetration or exposure). To put these results into context, the PIN is 35 450 for taking aspirin to avoid 1 death during the 6 months after a first nonhemorrhagic stroke, and the PIN is 324 for human papillomavirus vaccination in girls to prevent cervical cancer.

The duration of intervention was not statistically significantly associated with intervention effectiveness (mean [range] duration of interventions, 29.4 [1 to 144] weeks). The effectiveness of anti-bullying programs did not diminish over time during follow-up (mean [range] follow-up, 30.9 [2-104] weeks).

School-based alcohol-specific prevention programs have shown to be effective in a systematic review (Foxcroft et al., 2011a) of 53 RCTs in:

• reducing alcohol misuse in adolescents (statistically significant outcomes in 6 out of 11 alcohol-specific trials).

A review of 29 reviews (McGrath et al., 2006) found evidence in favour of the effectiveness of peer educators in school-based drug prevention programmes in:

• reducing all substances use at post-test (SMD = 0.24, 95 % CI 0.06–0.41, Z-test p < 0.01);
• reducing tobacco smoking at post-test (SMD = 0.17, 95 % CI 0.05–0.21, Z-test p < 0.01).

However, this relative effectiveness did not extend to 1 or 2 year follow-ups (McGrath et al., 2006).

School-based interactive programmes (i.e. those involving discussion) implemented in schools with predominantly special population, were found in a meta-analysis (Porath-Waller et al., 2010, 222 studies, N= 15 571) to be more effective than non-interactive programmes (i.e. a lecture) in:

• reducing smoking or non-smoking tobacco use, alcohol use or drinking/driving, “cannabis” or other illicit drugs’ use (SMD 0.21 vs. -0.05, p < 0.000);
• statistically significant delay in the onset of substance use;
• reducing youth cannabis use

School programmes based on a combination of social competence and social influence approaches were found in a systematic review (Faggiano et al., 2014) to be more effective than usual curricula in:

• reducing generic drug use at <12 months (RR 0.76, 95 % CI 0.64 to 0.89, 1 study, N=6362)

School programmes based on a combination of social competence and social influence approaches were found in a systematic review (Faggiano et al., 2014) to be more effective than usual curricula in:

• reducing cannabis use at 12+months follow-up (RR 0.83, 95 % CI 0.69 to 0.99, 6 studies, N=26 910);