|Support for proposition 3 - the assumptions of the RCT method are less relevant to trials of complex interventions|
|Findings in support of proposition||Evidence source|
|Trial 1||Trial 2||Trial 3||Trial 4||Trial 5||Trial 6||Trial 7|
|1. The contextual factors identified create a number of challenges for RCTs of complex interventions. Tensions exist between the methodological ideals of the RCT method and the reality of evaluating complex interventions within a real life setting and producing useful and meaningful evidence about that intervention.||✓✓||✓✓||✓✓||✓✓||✓✓||✓✓|
|2. Particular challenges exist in relation to achieving objectivity and standardisation. Personal contexts challenge the concepts of objectivity and equipoise, and all aspects of the reality of clinical practice can interfere with attempts to standardise interventions and protocols.||✓✓||✓||✓||✓✓||✓|
|3. The greater the dependence of the intervention and control arms of a trial on the SAME organisational and personal contexts the greater the likelihood that the distinction between the intervention and control will become blurred - contextual commonality.||✓✓||✓||✓✓||✓||✓|
|4. Changes in the organisational context can differentially impact on the delivery, and thus potentially on the effectiveness, of the intervention and the control.||✓✓||✓✓|
✓ = some evidence (one instance); ✓✓ = strong evidence (more than one instance); no check/tick = no specific evidence.
Wells et al.
Wells et al. Trials 2012 13:95 doi:10.1186/1745-6215-13-95