The mechanisms by which a whole-school intervention might improve sexual health: qualitative realist research nested in a trial in English secondary schools.

Seven distinct mechanisms were identified through which whole-school sexual health interventions might produce positive outcomes.

• The seven mechanisms were: improving knowledge using diverse pedagogies; improving confidence and ability to talk by normalising talk about sexual health; changing gender attitudes through challenging stereotypes; promoting access to sexual health services; building school engagement via new student roles; increasing inclusion of sexual-minority students; and reducing sexual harassment and abuse.
• These mechanisms were identified using 'dimensional analysis' of 52 interviews with teachers and 40 focus-groups involving 266 students from 22 English secondary schools.
• The research was conducted within the intervention arm of a randomised trial of the Positive Choices whole-school sexual health intervention conducted 2021-2025.
• Mechanisms were framed as 'context-mechanism-outcome configurations' within a realist evaluation framework, describing how interventions trigger mechanisms that interact with context to generate outcomes.

The mechanism of improving knowledge operated through the use of diverse pedagogies rather than standard classroom instruction alone.

• Diverse pedagogies were identified as the key trigger for knowledge improvement as a mechanism.
• This mechanism was identified through teacher interviews and student focus groups across 22 secondary schools.
• The Positive Choices intervention went beyond classroom education to modify school environments as part of its whole-school approach.

The intervention was proposed to improve students' confidence and ability to talk about sexual health by normalising such conversations.

• Normalisation of talk about sexual health was identified as the key mechanism through which confidence and communication ability improved.
• This mechanism was distinct from simple knowledge transfer, suggesting a social and cultural shift in how sexual health topics were treated within the school environment.
• Data came from 52 teacher interviews and 40 focus groups with 266 students across 22 schools.

The intervention was proposed to change gender attitudes by challenging stereotypes and providing students with insights into and empathy with others' perspectives.

• Challenging gender stereotypes and fostering empathy were identified as the operative mechanisms for changing attitudes.
• This mechanism was identified as novel in the context of whole-school sexual health interventions.
• Data were drawn from qualitative analysis across 22 English secondary schools in the intervention arm of the trial.

The intervention was proposed to promote student access to sexual health and other services by helping students understand their needs and entitlements.

• The mechanism involved students gaining awareness of their needs and entitlements, which in turn promoted access to services.
• This went beyond direct provision of services to address students' understanding of when and how to seek help.
• Findings were derived from 52 teacher interviews and 40 student focus groups across 22 schools.

School engagement was proposed to increase through the intervention by providing students with new roles on decision-making groups.

• Student participation in decision-making groups was identified as the specific mechanism by which school engagement was built.
• This represents a structural feature of the whole-school approach, going beyond classroom-level activities.
• The mechanism was identified through qualitative data from 22 secondary schools in the intervention arm of the trial.

The intervention was proposed to increase inclusion of sexual-minority students by normalising consideration of non-heterosexual identities and practices.

• Normalisation of non-heterosexual identities and practices within school settings was identified as the operative mechanism for increasing sexual-minority inclusion.
• This mechanism was described as one of the novel mechanisms identified by the research.
• Data came from focus groups involving 266 students and interviews with teachers across 22 English secondary schools.

The intervention was proposed to reduce sexual harassment and abuse by helping students understand consent and when to intervene in harassment situations.

• Two sub-mechanisms were identified: improving understanding of consent, and promoting bystander intervention in harassment situations.
• This was identified as one of the novel mechanisms through which whole-school interventions might promote sexual health.
• Findings were based on qualitative analysis using dimensional analysis of data from 22 secondary schools.

Three key contextual contingencies were identified that moderated whether and how the mechanisms operated.

• The three contingencies were: high initial student needs; teacher skills and commitment; and school commitment and capacity.
• These contextual factors were identified as influencing the degree to which the intervention's mechanisms were triggered and produced outcomes.
• The identification of contextual contingencies is consistent with the realist evaluation framework used, which examines how context interacts with mechanisms to generate outcomes.

The study used a qualitative realist evaluation framework with dimensional analysis applied to data from 52 teacher interviews and 40 student focus groups across 22 schools.

• Focus groups involved 266 students in total across 22 English secondary schools.
• The study was nested in the intervention arm of a randomised trial of the Positive Choices whole-school sexual health intervention, conducted 2021-2025.
• Dimensional analysis was the analytic method used to build context-mechanism-outcome configurations.
• The authors note that 'quantitative analyses will now be conducted to examine these mechanisms and contingencies.'