Effectiveness research: Nature, methods, and role in the validation of evidence-based interventions
The use of evidence-based interventions is increasingly valued in the psychosocial domain, but their process of validation remains controversial. Research on evidence-based interventions has been dominated by efficacy trials, which aim to test the effects of interventions under optimal conditions. However, conclusions from these studies may be difficult to translate in ordinary clinical practice. It is increasingly recognized that efficacy trials should be complemented by effectiveness trials, which aim to test the effects of interventions under real-world conditions. Effectiveness research now occupies an important place in the international scientific literature, but this type of research still has limited visibility in the francophone literature in Quebec and around the world. The aims of this article are to define effectiveness research, to present its main methods, and to highlight its implications for the validation and definition of evidence-based interventions. Effectiveness research often represents the first ‘reality check’ for an intervention occurring between efficacy research and dissemination or implementation research. This research involves attempting to find a balance between contradictory methodological orientations: to maximize ecological validity, external validity, and practical utility on one side and to preserve internal validity on the other. Through this balance, effectiveness research has the potential to produce evidence that is relevant, applicable, and generalizable, yet also robust. Effectiveness research is increasingly playing a key role in the validation of evidence-based interventions and should become a priority in Quebec.