The Cochrane Review moving beyond RCTs: philosophical notions of causality and its implications

Article type
Authors
Chandler J1
1The Cochrane Collaboration, United Kingdom
Abstract
Background:
Cochrane’s rigorous and well-established methodology, and reproducible methods to conduct meta-analyses of randomized controlled trials, although not exclusively, is under pressure. A more flexible systematic review structure that addresses broader questions other than intervention effectiveness and incorporates non-randomized designs and qualitative research, for example, are pushing forward. Cochrane already includes diagnostic test accuracy reviews and is evaluating extending this to prognostic reviews. Other systematic approaches seek to come under the Cochrane umbrella such as rapid reviews and mixed methods synthesis. This increasing methodological diversification in Cochrane brings challenges to the underpinning premise and assumptions of what constitutes ‘evidence’ in the evidence based medicine (EBM) hierarchy and the systematic synthesis of RCTs; which allows conclusions to be drawn about causality even if the conclusion does not transfer the application of the findings to real world situations.

Discussion:
This oral presentation will briefly outline some of the recent philosophical developments in causation. The purpose is to consider the implications these shifts in thinking have on notions of causality within the EBM paradigm as espoused by Cochrane. Causation is, often implicit through methodology and methods and thereby for the interpretation of results. Assumptions of causality need to be more explicit as experimental, observational and qualitative methods are increasing used in studies and systematic reviews. Current debates on notions of causality in philosophy have become increasingly active in the last two decades, addressing qualitative reasoning, mechanistic reasoning, thick causality (causal pluralism) and mathematical developments using causal diagrams. In focusing on the need for applicable evidence that has utility for users of Cochrane Reviews, that is the metaphysics of causation should be tied to methods on the one hand but must be equally tied to use in the target situation. These debates propose a broader approach to evidence and causal assumptions, and will be presented for discussion.