Normalisation process theory: a framework for developing, evaluating and implementing complex interventions

TLDR

Complex health interventions require effective evaluation, broad implementation, and normalization into routine practice, yet a gap persists between research and implementation. The authors propose using Normalisation Process Theory as a sensitizing tool to guide the design and evaluation of complex interventions and encourage trialists to adopt it. NPT offers a consistent framework that helps trialists describe, assess, and enhance implementation potential by highlighting feasibility, recruitment, data‑collection issues, and compatibility with clinical practice.

Abstract

The past decade has seen considerable interest in the development and evaluation of complex interventions to improve health. Such interventions can only have a significant impact on health and health care if they are shown to be effective when tested, are capable of being widely implemented and can be normalised into routine practice. To date, there is still a problematic gap between research and implementation. The Normalisation Process Theory (NPT) addresses the factors needed for successful implementation and integration of interventions into routine work (normalisation). In this paper, we suggest that the NPT can act as a sensitising tool, enabling researchers to think through issues of implementation while designing a complex intervention and its evaluation. The need to ensure trial procedures that are feasible and compatible with clinical practice is not limited to trials of complex interventions, and NPT may improve trial design by highlighting potential problems with recruitment or data collection, as well as ensuring the intervention has good implementation potential. The NPT is a new theory which offers trialists a consistent framework that can be used to describe, assess and enhance implementation potential. We encourage trialists to consider using it in their next trial.