Background It is critically important to determine the effectiveness of an intervention before it can be translated into clinical practice. However, the future implementation and sustainability of the intervention may be diminished if other intervention parameters are not assessed. This requires obtaining feedback from intervention recipients so interventions will be perceived as appealing, relevant, meaningful and beneficial to them; otherwise recipients may be unlikely to perform them over time, resulting in unsuccessful health outcomes.

Aim To propose the addition of two intervention parameters to the existing six-parameter model and provide examples from recent research of how each parameter can be tested.

Discussion Definitions of the eight parameters are provided and methods for analysing each of them explained. While some studies show necessity, fidelity and cost have unique distinguishing characteristics, other studies indicate feasibility, acceptability and safety have common features, and efficacy and effectiveness are closely associated.

Conclusion Researchers frequently examine one or two parameters, but few simultaneously apply the six-parameter model. This model is also missing two vital parameters – efficacy and cost.

Implications for practice Comprehensive and systematic evaluation of all eight intervention parameters is recommended before researchers begin randomised controlled trials and translate them into practice.