Table 3.
Results of the studies
| ID | Authors | Follow-up | Outcome | Effecta | p value | Test or analysis | Unit of observation | Comments | |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Berk-Seligson et al. (2014) | 29 months | Perception of homicides in the neighbourhood | − | 40 % | p ≤ 0.05 | Multilevel model | Adult population | Adjusting for co-variates and also by sampling design |
| Perception of youth in gangs within the neighbourhood | − | 14 % | p ≤ 0.05 | ||||||
| Perception of gang fights in the neighbourhood | − | 12 % | p ≤ 0.05 | ||||||
| 2 | Berthelon and Kruger (2011) | 48 months | Violent crimes (assaults, homicides, rape and offenses) committed by juveniles (among 14-17 years old) | − | 11 % | p ≤ 0.05 | Fixed-effects regression |
Municipality | Adjusting for co-variates |
| Property juvenile crimes (among 14-17 years old) | − | 24 % | p ≤ 0.01 | ||||||
| Total juvenile crimes (among 14-17 years old) | − | 19 % | p ≤ 0.01 | ||||||
| 3 | Kenney and Godson (2002) | 4 months | Involvement in deviant activities (theft, vandalism and disorderly conduct), San Diego | + | NS | NS | NS | Students | Outcome reported narratively; no p values mentioned |
| Involvement in deviant activities (theft, vandalism and disorderly conduct), Tijuana | No differences | NS | |||||||
| 4 | Muñoz-Vallejos and Rosales-Donoso (2008) | 12 months | Perception of fights as an event occurring at school | − | 17 % | p ≤ 0.01 | t test | Students | Not all the outcomes are presented as % or with a level of significance |
| Perception of threats as an event occurring at school | − | 9 % | p ≤ 0.05 | ||||||
| Perception of fights or threats in school per week | − | 0.86 (µ) | p ≤ 0.05 | ||||||
| 5 | Pérez et al. (2013) | 20 months | Witnessed bullying in the school | − | 0.99 (µ) | p ≤ 0.01 | t test | Students | Measured using scales. When using items from the witness scale there were 2 significant reductions |
| Committed/experienced serious bullying | − | 0.02 (µ) | p > 0.1 | ||||||
| Committed bullying | − | 0.09 (µ) | p > 0.1 | ||||||
| 6 | Reyes-Moreno (2011) | 2 months | Involvement in antisocial behaviours | − | 0.40 (µ) | p ≤ 0.01 | Signed-rank test | Students | Measured using scales |
| Involvement in intentional aggression | + | 0.30 (µ) | p ≤ 0.01 | ||||||
| Involvement in delinquency | + | 0.10 (µ) | p ≤ 0.01 | ||||||
| 7 | Silveira et al. (2010) | 32–36 months | Average of monthly homicides (vs violent favelas) | − | 69 % | NSb | Generalised linear model | Areas/favelas | All comparsions were significant when comparing with baseline values but were not different when comparing within the follow-ups |
| Average of monthly homicides (vs non-violent favelas) | − | 64 % | NSb | ||||||
| Average of monthly homicides (vs neighborhoods) | − | 60 % | NSb | ||||||
| 53–84 months | Average of monthly homicides (vs violent favelas) | − | 61 % | NSb | |||||
| Average of monthly homicides (vs non-violent favelas) | − | 52 % | NSb | ||||||
| Average of monthly homicides (vs other neighborhoods) | − | 69 % | NSb | ||||||
| 8 | Varela et al. (2009); Tijmes and Varela (2008) | 24 months | School 1 Perception of fights in the school | − | 10 % | p ≤ 0.05 | t test | Students | Results for school 2 not clear; not statistical significance provided for all the mentioned outcomes |
| School 1 Perception of robbery in the school | − | 8 % | p ≤ 0.05 | ||||||
| School 1 Perception of intentional damages to school | − | 12 % | p ≤ 0.05 | ||||||
| School 1 Perception of threats, students to teachers | − | 8 % | NS | ||||||
| School 1 Perception of aggression, students to teachers | − | 7 % | NS | ||||||
| School 1 Perception of insults, students to teachers | − | 11 % | NS | ||||||
| School 2 Perception of robbery in the school | + | 19 % | p ≤ 0.05 | ||||||
| School 3 Perception of threats among students | + | 14 % | p ≤ 0.05 | ||||||
| School 3 Perception of insults among students | + | 9 % | NS | ||||||
| School 3 Perception of robbery in the school | + | 17 % | NS | ||||||
| 9 | Varela (2011) | 29 months | Witnessed antisocial behaviours | − | 0.16 (µ) | p ≤ 0.01 | t test | Students | Measured using scales; not statistical significance provided for all the mentioned outcomes |
| Witnessed violence between peers | − | 0.17 (µ) | p ≤ 0.01 | ||||||
| Witnessed violence, students to adults | − | 0.34 (µ) | p ≤ 0.01 | ||||||
| Committed violence to peers | − | 0.14 (µ) | p ≤ 0.01 | ||||||
| Committed serious violent acts to peers or to teachers | − | 0.03 (µ) | p > 0.1 | ||||||
A systematic review of interventions to prevent youth violence. Latin America, 2015
NS not specified because results were described narratively but not numerical
+Increase over time or higher proportion/values among the intervention group. Effects presented as percentage or difference in means when stated
aReduction over time or lower proportion/values among the intervention group
bSignificant results using confidence intervals but p values not reported