Christine Stirling: Move over RCT—time for a revised approach to evidence based medicine

We are stifling our capacity to use research evidence for patient centred outcomes by privileging RCTs

In the two decades since Sackett et al outlined their definitive account of evidence based medicine (EBM) and evidence hierarchies in The BMJ, randomised controlled trials (RCTs) have gained a position of overwhelming dominance that appears to surpass the original intent of EBM.

From the first publication of an RCT in 1948 to today, RCTs have come to dominate the evidence landscape, gaining both research prestige (which translates to funding and publications) and medical authority. RCTs are now often considered the best form of evidence in most evidence hierarchies—particularly if combined as systematic reviews. I find myself increasingly frustrated with this status when I participate in grant review panels and believe it is time to shake things up and speed up changes to this mindset.

There has already been increasing acknowledgement that the EBM movement should reconsider RCTs’ pre-eminence and be open to evidence collected from other methods. The limitations of RCTs are becoming more widely recognised. Some argue that RCTs are reductionist, and that they fail to incorporate patient values and complexities. It’s been pointed out that even an ideal RCT has limited generalisability in answering research questions that help us understand which treatments work for which individuals. And it’s been highlighted that, despite commentators’ praise for how RCTs prevent bias and confounding, in reality many of them have enough flaws that they cannot justify quality claims over observational studies.

Research evidence users (including health professionals) can still be led to frequently ignore these “lower levels” of evidence, with the number of Cochrane reviews that only consider RCTs a good indication of this. We are starting to see some adjustments to hierarchies in new guidelines, such as GRADES, although they still privilege RCTs and can inappropriately ignore other valid forms of evidence. NICE guidelines are another example of efforts to include different levels of evidence and expert opinion into clinical recommendations. Yet RCTs are still well entrenched into our research training, funding, and publication systems as “gold standard’.

While it will take many years to unravel the systems and infrastructure that prioritise RCTs, health professionals and educators can still easily move towards using a wider range of evidence. This will require firstly a change in mindset and adjustments to education curricula, but guidance is available for thinking about the best study design to use in relation to the clinical question.

If we wish to improve clinical care, health services, and patient outcomes we will need to continue developing new ways of valuing and using evidence. Person centred medicine provides an impetus to do this, with its focus on models of clinical decision making that balance patient values and individual traits with clinician expertise and available knowledge.

Providing care in the era of “big data” also aids this endeavour. With a larger volume and variety of data to access and analyse, observational studies may deliver better quality evidence, which incorporates subgroup analysis and heterogeneity more cost effectively than RCTs. Linking N of 1 studies through large databases could also strengthen this individual trial method and provide impetus for more clinician based research. The time is ripe for further developing this precision research approach, with increasingly technology aware patients creating the potential for coordinated N of 1 trials that research with patients. An Australian example of this resulted in treatments changes for 28 of 64 children with attention-deficit/hyperactivity disorder.

For many clinicians the privileging of RCT evidence over other valid forms of evidence impacts clinical decision making as it leaves them with a limited range of evidence to use. As our capacity to share and process information globally increases, so does our ability to analyse large data sets, but this doesn’t have to take the form of data in the traditional sense and it doesn’t have to be only clinicians and researchers who are doing the sharing. Patient blogs and forums allow patients to share stories globally and for anecdotal treatment results to be publicly documented—providing a rich source of patient stories and outcomes.

Our ability to communicate and analyse big data needs to be met with revised methodologies and innovation, but this requires a wider debate, changes to funding priorities, and a focus on evidence that fits the clinical question. With revised research evidence frameworks and methods, health professionals could have improved access to, and understanding of, more relevant research evidence for clinical decisions.

Christine Stirling is a mixed methods health services researcher with the University of Tasmania.

Competing interests: None declared