Dismissing Randomised Controlled Trials seems to be an increasingly popular thing to do these days – well, we are living in strange times…Last year Sally Cupitt (Head of NCVO Charities Evaluation Service) asked whether RCTs were the gold standard or just ‘fool’s gold’? A few weeks ago eminent professors Angus Deaton and Nancy Cartwright set out (in a suitably academic manner) their conclusions on the ‘limitations of randomised controlled trials’. Now NfP Synergy’s Joe Saxton has jumped aboard the anti-RCT bandwagon describing them as ‘another false dawn’ and ‘evaluation fantasy’.
Whilst it may make for a good blog post to challenge the growing awareness of and interest in Randomised Controlled Trials, it’s neither helpful nor accurate to dismiss their benefits so readily.
Let’s look at some of the criticisms levelled at RCTs:
- RCTs are ‘fraught with problems and complexity’ and Nesta’s guide to RCTs is 73 pages long so this must be true.
Some RCTs are complex (though if we are tackling complex challenges in the charity sector –see point 4 below – should we be so scared of complex methods of evaluating impact?). Some are too complicated. But the existence of some poor practice doesn’t justify dismissing an entire method. That’s the sort of insidious thinking that has led some thinkers and politicians to characterise all charities as; poorly run, self-interested, inefficient ‘sock puppets’ of the State. Surely we don’t wish to subscribe to that type of logic?
There is a tendency, as with many specialist techniques to shroud them in complexity and technicality which serves the interests of experts and prevents their wider application. This does not make the method complex or problematic. It merely highlights the need for better understanding, support and application.
- Nobody mentions double-blinds.
Apart from the fact they do if you are inclined to delve into the academic literature, the real issue here is that it is a red-herring. That’s the sort of sentiment which prevents RCTs from becoming a mainstream evaluation tool. It doesn’t matter if you don’t run a double-blind trial. Let’s be pragmatic about things – there are things which are essential in running trials and things which are ‘nice to haves’. In fact, we could talk about experimental methods as a continuum on which RCTs is one approach. It might be the one we aspire to – as reasons of complexity, scale and proportionate costs can make it impractical – but it’s not right for every occasion. Not even the most ardent trial evangelist would consider suggesting that. But there are plenty of instances where they can significantly enhance current practice.
- It is unethical to withhold an intervention from some (randomly selected) people
This one just makes me laugh and cry in equal measure as it displays an absurd degree of selection bias and wholly misrepresents the very notion of understanding what works. Firstly, if you know something is going to provide a benefit to a particular group then do not (ever!) waste time on a trial. Just do it. Give it to the people as soon as possible.
But if, on the other hand, you think an intervention is going to be effective but you’d like to know for sure if it works a trial could give you confidence in the result. When we test new interventions we don’t know if they are going to work, we are testing them. Sometimes the things we ‘know to be true’ turn out not to be when properly tested. A classic example of this is the treatment of serious head injuries with steroids which had been the standard medical practice for 30 years, until someone tested it through an RCT and immediately found steroids were killing people. And so what was known to be true changed…overnight.
Then there’s the convenient overlooking of the fact that running a pilot is considered perfectly reasonable – indeed the post goes on, without a hint of irony, to talk about an intervention in one South London school…but why was it run in only one school? Was it ethical to deprive students in other schools of this intervention?
Somehow it’s perfectly fine to run a pilot but unethical to run a trial. Hmmmm…
- Measuring single variables isn’t realistic when charities are often tackling complex challenges
This is more of an argument for RCTs than against them as far as I am concerned. It’s precisely because of the complexity that understanding the impact of single variables is useful. RCTs allow us to separate out the other ‘background noise’ and determine just what difference the intervention makes. Of course, that doesn’t mean it’s necessarily sensible to use trials for longitudinal studies where the impact may take place over a generation. RCTs, like every other evaluation method needs to be used appropriately.
What we have found in our work is that small things can make a big difference – changing the text in how we communicate, altering the way information is presented, how we ask someone to do something or the way we design a service to be more customer-centric. All these things can make a significant difference to our impact and I’d suggest it’s our moral duty to put our assumptions to the test.
- The sample size needs to be big
Yes, it does. So it’s not always going to be appropriate to run a trial in every circumstance – and it’s possible in these instances to use experimental methods without running full-blown trials. It’s also very valuable to recognise the limitations of what we are doing. No one is saying that we must run trials on everything…but we must avoid over-confidence in attributing change to our interventions without considering other external players and environmental factors. To dismiss RCTs simply because they don’t work in every instance is frankly ridiculous.
Contrary to what is suggested there are innumerable instances where RCTs will work, are not overly complex or prohibitively expensive and wholly achievable for a great number of charities (indeed where scale or resources are an issue trials might even be a catalyst for collaborating to share learning and increase efficiency).
‘Why have an evaluation standard that is applicable to very few of the interventions that charities make?’
Ummm…because I thought we were in the business of trying to raise standards and quality in the charity sector.
There needs to be an intelligent understanding of what RCTs are, how they work and when it is appropriate to use them. If the starting point of those seeking to support improvement of evaluation and impact assessment in the sector is to rubbish an entire method simply because it’s not a panacea for all the sectors ills, what chance do we have of that?
And if anyone would like some suggestions of practical ways in which RCTs could easily be used by charities feel free to get in touch and I’d be more than happy to oblige.
Views expressed are the author’s own and do not necessarily represent those of the Alliance for Useful Evidence. Remember you can join us (it’s free and open to all) and find out more about the how we champion the use of evidence in social policy and practice.