Applying a realist(ic) framework to the evaluation of a new model of emergency department based mental health nursing practice.

Evaluation has become progressively popular within public health and healthcare programme research, with an emphasis on outcomes and a desire to improve practice and service delivery. Mixed methods approaches are consequently being employed to capture the multidimensional characteristics of programmes that aim to address problematic situations affecting targeted populations. This paper provides an overview of critical realism, a modern philosophical perspective that seeks contextualised causal understandings of social phenomena. Realistic evaluation, a research methodology adapted from critical realism, is highlighted as a means of obtaining a deeper appreciation of how complex programmes work, for whom they work, and under what circumstances. The evaluation of a mental health nurse practitioner outpatient service based in the emergency department of a large teaching hospital in Sydney Australia is used to illustrate the application of a realist perspective to research in nursing practice.