Table 5 Domains of implementation strategies for dimensions of external validity of social network intervention studies

Actor

Members of school social networks were those who enacted the strategies.

Pragmatic since the actors of interventions were students in usual education settings.

The analyzed SNI studies were based on already established school social networks.

The action

Students received information to generate peer pressure or training to be supporters and leaders, to disseminate information, and to influence PA and SB positively.

Explanatory, considering that some of the SNI were implemented with the assistance of non-school staff, something that only sometimes occurs in schools. However, most of the activities may be implemented by school staff and are aligned with the usual strategies used in school settings.

The domains of adoption (staff) and implementation of SNI were moderately well described. However, adoption and implementation costs were not frequently reported.

Action targets

Actors may require training to perform their assigned roles within the social network. The training was focused on increasing social skills and knowledge.

Pragmatic because the studied SNI takes advantage of learning social skills fostered in the classroom and the social interactions that naturally occur within schools.

The theories used to develop the analyzed SNI offer a wide range of social mechanisms to promote the intended behavior: social influence, social support, social modeling, social pressure, and social norms.

Temporality

The duration of the SNI ranged from one week to 10 months, and training stages were reported.

The analyzed SNI were more pragmatic than explanatory because temporality is easily covered during a usual school year.

Although in most of the studies, the temporality of the SNI was reported, the frequency and content of the social interactions that take place within the school social networks are challenging to control and monitor.

Dose

The number of sessions or contacts ranged from two contacts per week to one per month. In some studies, this information needed to be provided.

Pragmatic because the highest dose of the studied SNI is easily reached in usual school settings.

The reported dose applies to the traditional schedule of school settings.

Implementation outcomes

Strategies for intervention fidelity and assessment of fidelity should be improved in the report of SNI.

Most of the analyzed SNI reported high flexibility of adherence and implemented non-mandatory activities; therefore, analyzed SNI were pragmatic.

Most SNI did not report enough information about three implementation outcomes: adoption, costs, and maintenance.

Theoretical justification

All the studied SNI reported theoretical justification.

This domain is not explored in the PRECIS-2 tool.

All the studied SNI reported theoretical justification. In addition, all the studies explored characteristics of the already and naturally established social networks within the schools. This examination is a critical key in SNI and is considered a “determinant of practice”.