Using normalisation process theory to develop a complex intervention: A qualitative case study of screening for homelessness in healthcare settings

BACKGROUND AND AIMS: Normalisation Process Theory (NPT) seeks to describe and explain how a complex intervention can be embedded into an existing health and social care system. NPT is frequently used to evaluate interventions, and less frequently to design them.We demonstrate how NPT can be applied to exploratory qualitative data to understand the potential barriers and facilitators to the implementation of a new intervention in a health setting using the NPT framework. We illustrate this application using a case study of screening for homelessness and housing instability in Australian emergency department and primary care settings. 

METHODS: This qualitative study comprised semi-structured interviews of healthcare workers and people with lived experience of homelessness. Our hybrid analysis involved an initial inductive reflexive thematic approach followed by deductive qualitative analysis guided by a theoretical framework, that is, the four domains of NPT: Coherence, Cognitive Participation, Collective Action and Reflexive Monitoring. 

RESULTS: 39 interviews were conducted with healthcare workers (n = 30) and people with lived experience of homelessness (n = 9). Healthcare workers differentiated screening for homelessness from their current work (Coherence) but had mixed views on the utility of screening (Cognitive Participation) and were reluctant to do the extra work (Collective Action). Healthcare workers from Aboriginal Community Controlled Health Organisations and community health centres demonstrated higher commitment and readiness to do this work than their counterparts in hospital or fee-for-service primary care settings. People with lived experience of homelessness wanted their healthcare workers to understand how their housing situation affected their health, and to adapt care accordingly. 

CONCLUSION: This study demonstrates that NPT can be used in the very early planning of interventions. This application of NPT may support the intervention design that is better aligned to the expectations of people tasked with implementing the intervention, thus increasing uptake and facilitating normalisation.