Xchange prevention registry

Beneficial: Interventions for which convincing, consistent and sustained effects for relevant outcomes are in favour of the intervention as found in two or more studies of excellent quality in Europe.

Likely to be beneficial: Interventions for which convincing and consistent effects for relevant outcomes are in favour of the intervention as found in at least one evaluation study of excellent quality in Europe.

Possibly beneficial: Interventions for which some effects for relevant outcomes are in favour of the intervention as found in at least one evaluation study of acceptable quality in Europe. An intervention ranked as ‘possibly beneficial’ is suitable for application in the context of more rigorous evaluations.

Additional studies recommended: Interventions for which concerns about evaluation quality or consistency of outcomes in Europe make it difficult to assess if they are effective or not, even if outcomes seem to be in favour of the intervention.

Unlikely to be beneficial: Interventions for which at least one evaluation of excellent quality in Europe shows convincing evidence of no or harmful effects on relevant outcomes.

Possibly harmful: Interventions for which some effects for relevant outcomes of the intervention are considered harmful, as found in at least one evaluation study of acceptable quality in Europe. An intervention ranked as 'possibly harmful' is unsuitable for application except within a framework of other priorities and with rigorous and strictly supervised evaluations.