HCS: Case study, Context and Complex interventions (TRIPLE C) - development of guidance and publication standards to support case study-based research

Complex interventions (e.g. redesign of stroke services, urban regeneration programmes) are widely used in the health service and in public health practice. The issue of how one develops, implements and evaluates complex interventions remains a key one for researchers. Traditional research methods have been stretched to the limit in meeting this challenge. There has been growing interest in developing research methods that support improved development and implementation in health care, and in ways that account for the contexts (communities, organisations and so on) in which complex interventions are intended. Case study research is widely recognised as offering such methods, and as a vital resource for understanding the influence of context on complex interventions. A significant literature on case study research already exists in health services research and the social sciences. This literature has evolved out of different disciplines (e.g. psychology, sociology, management), and research traditions (e.g. qualitative or quantitative). It has yet to be interrogated in a way that can support improved development and implementation of complex interventions in health care and public health.

Traditional approaches to systematic literature review attempt to collate all evidence that fits pre-specified eligibility criteria in order to answer a specific research question. Such approaches lend themselves to certain (often quite narrow) areas of work but tend to be far less helpful when reviewing diverse, cross-disciplinary topics like the role of case study research in evaluating complex interventions. We therefore propose a meta-narrative review: in other words, using a systematic, theory-driven technique to guide reviewing the wide-ranging literature on case study methods and help us to understand how such methods have been differently conceptualised and used by different groups of researchers. Meta-narrative review is an on-going process, involving the reviewer in understanding what will be most useful to the intended audience, illuminating the topic from multiple angles, capturing how research traditions have unfolded over time, examining 'conflicting data' from different research traditions, continually reflecting on emerging findings and gaining feedback from an external audience to guide further reflection and analysis. We will combine data from key sources to produce an account of how and why case study traditions have evolved, and then compare findings from these different traditions to build a rich picture of case study research on complex interventions from multiple perspectives.

Having summarised the relevant literature, we will conduct an online survey with a group of up to 30 experts in case study research (ensuring a range of perspectives, organisations and locations). The idea will be to share our summary of the literature with the group, stimulate reflection and (over three rounds of online discussion) work towards getting as close as possible to consensus on draft guidance on the use of case study when researching complex interventions. We plan to then test this draft guidance with up to five teams of researchers who have conducted and published highly regarded case studies of complex interventions, as well as a group of up to 10 case study experts.

Through this iterative process, we will develop methodological guidance on how to design and carry out case studies of complex interventions in health care, and publish standards for case study-based research on complex interventions. We will make these freely available. We also plan to build a community of practice around case study research in this field, bringing together experts from different disciplines and traditions to inform future development, implementation and evaluation of complex system-level interventions.

There is increasing recognition that the conventional scientific quest for certainty, predictability and linear causality (often via RCTs) needs to be augmented by the study of how we can best deal with uncertainty, unpredictability and emergent causality. Case study research offers a vital resource for such research, and for those keen to develop methods that support meaningful evaluation of complex interventions in health care.

The literature on case study methodology is diverse, drawing on varied disciplines and epistemologies. It has yet to be formally evaluated in ways that allow researchers, funders and decision makers to better understand the interaction between context and the implementation of complex system-level interventions over time. This study asks: What are the key steps in producing case study research into the influences of context on complex system-level interventions that advances knowledge and informs policy and practice? How might 'high' and 'low' quality in such case studies be defined and assessed? And, how can such case study research best be reported in order to maximise value? It uses meta-narrative review to collate and summarise diverse literature on case study methods, including the range of theoretical and methodological approaches to studying contextual influences; combined with an online Delphi survey with an international and interdisciplinary panel of up to 30 case study experts from academia, policy and practice. The output will be draft methodological guidance and publication standards for case study in health system and public health research. This will be piloted with 3-5 research teams that have published exemplar (i.e. highly-cited) case studies, and with a panel of 10 external experts, to consider the extent to which the range of case study methods have been adhered to by real-world case studies and refine guidance. Final guidance/standards will be disseminated via social media, journals and a knowledge sharing event.

Following the Medical Research Council's Highlight Notice on 'Case study-based research for context in complex interventions', this study focuses on reviewing the state-of-the-art in methodologies for the design, conduct, analysis and reporting of case study-based research and developing/piloting related guidance. As such the key intended beneficiaries are academic researchers, particularly those interested in the interrelation of context with complex system-level interventions (see Academic Beneficiaries section). In addition, we anticipate that the research will benefit three key groups:

JOURNAL EDITORS AND REVIEWERS: by providing clear and accessible publication standards for case study research relating to complex system-level interventions on which they can draw to assess the quality of submitted case study research.

HEALTH SYSTEMS/PUBLIC HEALTH RESEARCH FUNDERS: by setting out standards for assessing quality in the design, conduct, analysis and reporting of case studies in (covering areas such as case selection, generalisability, characterisation of mechanisms, context and their interrelation, and methods for synthesising the findings of case studies) that can inform decisions about funding.

COMMISSIONERS/PATIENTS/CITIZENS: In the longer term, by supporting case study research that can support meaningful development and implementation of complex interventions across different contexts in health systems and public health practice.