Evaluating complex interventions in context: systematic, meta-narrative review of case study approaches

Area of Science:

• Health systems research
• Public health research
• Complex interventions

Background:

• Growing need for methods capturing dynamic interactions between context and complex intervention implementation.
• Case study research offers in-depth understanding but lacks guidance for complex intervention evaluation.
• Limited guidance exists on best practices for using case study approaches in complex intervention evaluation.

Purpose of the Study:

• To review and synthesize literature on case study research across disciplines.
• To determine the relevance of case study research to contextual influences on complex interventions in health systems and public health.
• To provide guidance on using case study research for evaluating complex interventions.

Main Methods:

• Systematic meta-narrative review of literature.
• Scoping review of seminal texts on case study methodology, context, complexity, and interventions (n=60).
• Detailed review of empirical literature on case study, context, and complex interventions (n=71).
• Identification and review of hybrid papers on case study merits and challenges in complex intervention evaluation (n=8).

Main Results:

• Identified four overlapping research traditions using case study differently: intervention development/testing, organizational change analysis, realist evaluations, and naturalistic complex change studies.
• Each tradition conceptualized context differently: backdrop/influencing factors, interacting conditions, triggering circumstances, or socially structured practices.
• Few studies problematized the definition of 'case' and 'context' or their implications for methods and knowledge production.

Conclusions:

• Case study research for complex interventions draws on diverse traditions with implicit methodological preferences and consequences for knowledge production.
• The implicit nature of approaches and their consequences impact understanding, implementation, and evaluation of complex interventions.
• Strong recommendation for deeper engagement with case study research as a methodology to improve evaluation of complex interventions.