Background:
A number of single case reports have suggested that the context within which intervention studies take place may challenge the assumptions that underpin RCTs. However, the diverse ways in which context may challenge the central tenets of the RCT, and the degree to which this information is known to researchers and/or subsequently reported, has received much less attention. In this paper we explore these issues by focussing on 7 RCTs of interventions ranging in type and degree of complexity, and across diverse contexts.
Methods:
This in-depth multiple case study using interviews, focus groups and documentary analysis was conducted in two phases. In phase one, a RCT of a nurse-led intervention provided a single exploratory case and informed the design, sampling and data collection within the main study. Phase two consisted of a multiple explanatory case study covering a range of trials of different types of complex intervention. A total of 84 data sources across the 7 trials were accessed.
Results:
We present consistent empirical evidence across all trials to indicate that four key elements of context (personal, organisational, trial and problem context) are crucial to understanding how a complex intervention works and to enable both assessments of internal validity and likely generalizability to other settings. The ways in which context challenged trial operation was often complex, idiosyncratic, and subtle; often falling outside of current trial reporting formats. However, information on such issues appeared to be available via first hand "insider accounts" of each trial suggesting that improved reporting on the role of context is possible.
Conclusions:
Sufficient detail about context needs to be understood and reported in RCTs of complex interventions, in order for the transferability of complex interventions to be assessed. Improved reporting formats that require and encourage the clarification of both general and project-specific threats to the likely internal and external validity need to be developed. In addition a cultural change is required in which the open and honest reporting of such issues is seen as an indicator of study strength and researcher integrity, rather than a symbol of a poor quality study or investigator ability.