Growing up without violence (GWV): Results of a cluster randomised trial of a school-based intervention preventing adolescent sexual abuse and exploitation in Brazil

A cluster randomised controlled trial in Brazil evaluating the "Growing up without violence" school-based intervention found no statistically significant improvement in adolescents' knowledge regarding child sexual abuse and exploitation risks compared to the control group.

The Gist

Imagine a massive school district in Brazil trying to protect its students from a hidden danger: sexual abuse and exploitation. The researchers decided to test a specific "safety manual" called Growing Up Without Violence (GWV). Think of this manual not as a book, but as a toolkit of videos, workshops, and lesson plans designed to teach teenagers how to spot danger, say "no," and know who to call for help.

Here is the story of how they tested it and what they found, explained simply:

The Experiment: A Coin Flip for Schools

The researchers didn't just pick a few schools to try the program. Instead, they treated it like a giant science experiment. They gathered 60 public schools in two busy coastal cities (Cabo and Jaboatão) known for having high rates of this type of abuse.

They flipped a coin for every school:

• Heads (Intervention Group): 30 schools got the "Safety Toolkit." Their teachers were trained on how to use the materials, and they taught the lessons to students.
• Tails (Control Group): 30 schools kept doing what they usually do. They followed the standard government rules (like holding a special awareness week in May) but didn't get the special training or the new curriculum.

Before the program started, they asked students, "Do you know what counts as abuse?" and "What would you do if someone tried to hurt you?" They asked the same questions again four months later to see if the "Safety Toolkit" made a difference.

The Result: The Toolkit Didn't Change the Score

The big question was: Did the students in the "Safety Toolkit" schools know more about safety than the students in the regular schools?

The answer was no.

• The Score: Imagine the test was out of 12 points. Before the program, both groups scored about 6.6. After the program, the "Toolkit" group scored 7.33, and the regular group scored 7.21.
• The Difference: That tiny gap of 0.12 points is so small that statistically, it's basically a tie. It's like if two runners started a race at the same time and finished with a difference of a single step. The researchers concluded that the program did not significantly improve the students' knowledge of sexual abuse risks compared to the schools that didn't get the program.

The "Why" Behind the Result

The researchers didn't just shrug and move on; they tried to figure out why the "Safety Toolkit" didn't seem to work. They looked at a few possibilities:

1. The Recipe Wasn't Followed: Even though the schools got the materials, not every teacher used them. Some schools didn't use any of the lessons at all. Others used only a few. It's like giving a chef a fancy new recipe but having them only use one ingredient.
2. The Effect Was Too Small: Maybe the program did help, but the help was so tiny that this specific test couldn't measure it.
3. The Wrong Target: Maybe the program helped students in ways the survey didn't ask about (like feeling more confident), but it didn't actually change their test scores on "what is abuse."
4. It Just Didn't Work: It's possible that this specific way of teaching just isn't effective for this specific problem.

A Glimmer of Hope (and a Caveat)

There was one interesting twist. When they looked at the data by gender, they saw a borderline hint that the program might have helped girls a little more than boys. The girls in the "Toolkit" schools showed a slightly bigger jump in knowledge than the boys did. However, this wasn't a strong, definitive proof, just a signal that suggests more research might be needed.

The Bottom Line

The researchers ran a very careful, large-scale test to see if teaching teenagers about sexual abuse in schools would work. They found that, in this specific case, the program did not lead to a measurable increase in students' knowledge compared to schools that didn't use the program.

They aren't saying the idea of school-based prevention is bad. Instead, they are saying, "We tried this specific version of the program, and it didn't show the results we hoped for." They suggest that before we spend more money and time on similar programs, we need to figure out how to make them work better, or perhaps try different strategies entirely.

Technical Summary

Technical Summary: Growing up without violence (GWV): Results of a cluster randomised trial of a school-based intervention preventing adolescent sexual abuse and exploitation in Brazil

Problem Statement
Child sexual abuse and exploitation (CSAE) constitute a pervasive public health crisis with severe, long-lasting physical and mental health consequences, including early pregnancy, STIs, depression, and PTSD. While global prevalence is high, evidence regarding the effectiveness of prevention interventions in low- and middle-income countries (LMICs) remains limited. In Brazil, particularly in the Recife Metropolitan Region, rates of adolescent sexual exploitation are significant, with a notable proportion of exploited adolescents still enrolled in school. Despite existing social services, schools often lack the specific protocols, training, and support necessary to detect, manage, and refer CSAE cases effectively.

Methodology
The study employed a two-arm, parallel, repeated cross-sectional cluster randomised controlled trial (cRCT) conducted in two municipalities in northeastern Brazil: Cabo de Santo Agostinho and Jaboatão dos Guararapes.

• Participants: 60 public schools (30 municipal, 30 state-run) were randomly allocated to intervention or control arms using stratified randomisation. From each school, approximately 50 students aged 12–17 were randomly selected for baseline and endline surveys.
• Intervention: The "Growing up Without Violence" (GWV) curriculum, developed by Canal Futura (a non-profit arm of the Roberto Marinho Foundation). The intervention involved capacity-building sessions for two teachers per school, covering themes such as family-based abuse, sexual exploitation, victim identification, active listening, and reporting mechanisms. Teachers were then expected to implement GWV resources (audiovisual content, workbooks, etc.) in classrooms.
• Control: Control schools adhered to standard national guidelines, which include awareness activities during the "National Day to Combat Abuse and Sexual Exploitation of Children and Adolescents" (May 18th) but received no specific GWV training or structured curriculum.
• Outcomes: The primary outcome was students' knowledge of CSAE risks, measured by the revised Children's Knowledge of Abuse Questionnaire (CKAQ-R) at endline, adjusted for baseline scores. Secondary outcomes included knowledge of online sex risks, intention to seek help for online abuse, and recall of participation in prevention activities.
• Analysis: Primary analysis used a cluster-level summary approach with linear regression, adjusted for baseline scores and randomisation strata. The study was powered to detect a standardised difference of 0.25.

Key Results

• Primary Outcome: The trial found no statistically significant difference in adolescents' CSAE risk knowledge between the intervention and control arms. The adjusted mean difference in CKAQ-R scores was 0.02 (95% CI -0.19 to 0.23, p = 0.87).
• Secondary Outcomes: No significant associations were found for knowledge of online sex risks (p = 0.313), intention to seek help for online abuse (p = 0.235), or recall of participation in prevention activities (p = 0.717).
• Subgroup Analysis: There was no evidence of interaction by age. However, borderline evidence of interaction by gender was observed (p = 0.032), suggesting a greater difference in knowledge scores among girls in the intervention arm compared to boys, though the overall main effect remained non-significant.
• Implementation (Dose-Response): An exploratory analysis categorizing schools by the number of GWV components implemented (low, high, or no data) showed no significant association between the level of implementation and knowledge scores (p = 0.559). Implementation fidelity was variable; only 20 of the 30 intervention schools provided implementation data, and the average number of components used was 3.7 out of the available materials.

Significance and Claims
The paper concludes that the GWV school-based intervention, as implemented in this trial, did not demonstrate a statistically significant effect on improving adolescents' knowledge of sexual abuse risks compared to standard care. The authors offer several potential explanations for this null result without attributing the failure to a single cause:

1. Implementation Fidelity: The intervention may not have been implemented with sufficient intensity or fidelity (e.g., teachers may have lacked time, materials, or confidence to address sensitive topics).
2. Effect Size: The true effect of the GWV curriculum might be minimal and below the study's detection threshold.
3. Unmeasured Outcomes: The intervention may have influenced outcomes other than knowledge (e.g., behavioral changes or reporting behaviors) that were not captured by the survey instruments.
4. Ineffectiveness: It is possible that the specific intervention design lacks effectiveness in this context.

The authors emphasize that further rigorous evaluations and implementation studies are essential to determine how resources should be directed toward effective CSAE prevention strategies. They do not claim the intervention is definitively ineffective but highlight the need for better understanding of implementation barriers and the necessity of measuring diverse outcomes beyond knowledge acquisition.