Randomised controlled trials (RCTs) are great, the gold standard of empirical research. The only thing better than RCTs are systematic reviews of lots and lots of RCTs. (So the story goes.) The reader may have noticed that RCTs evaluating CBT for psychosis have been vigorously debated for many months after a review was published in the British Journal of Psychiatry (Jauhar et al., 2014). Maybe not everyone agrees that RCTs are great (disclosure: I have analysed a couple), but I think it’s fair to say they are unavoidable whether you are trying to design or demolish them.
High-quality psychotherapy research by Patricia Arean and Helena Chmura Kraemer sets out to be a “practical, step-by-step guide” to designing and running RCTs. So why bother with an RCT? Observational trials, the authors explain, might involve studying participants who choose one of two or more interventions of interest by simply observing how they get on. This is problematic as differences in outcomes might be due to whatever factors led to them ending up receiving an intervention rather than the effect it had. RCTs use randomisation to overcome this problem so that people differ only in terms of the intervention received. That’s about it for the “why”: don’t expect debate on the epistemology.
The book’s strengths emerge as it develops: it catalogues issues that should worry study investigators and the authors draw on their own experience to offer hints. The Delphi consensus-building approach is introduced to solve the problem of developing an intervention manual and examples are given of how to word a letter asking for feedback on the proposed result. Randomisation techniques are introduced including horror stories of how they have gone wrong and invalidated RCTs. Ideas are provided for control groups, e.g., waiting list, usual care, and “gold standard” controls, and their strengths and drawbacks. The importance of not using pilot study results to determine sample size choices is explained. Guidance is provided on the people required; for example you need three or more therapists, at least two research assistants in case one takes ill, and a good statistician amongst other people. The Appendix includes a sample budget justification. All practical advice.
The text runs to under 200 pages so this could never be a comprehensive guide to all aspects of RCTs. What this book does do well is provide a systematic menu of options and ideas for things to consider. It might possibly give some ideas of what to demolish too, should you be so inclined, but this book is really only for those who are already sold on RCTs and want to get on with the seemingly painful task of designing and running one.
Areán, P. A., & Kraemer, H. C. (2013). High-quality psychotherapy research: from conception to piloting to national trials. Oxford University Press.
Jauhar, S., McKenna, P. J., Radua, J., Fung, E., Salvador, R., & Laws, K. R. (2014). Cognitive-behavioural therapy for the symptoms of schizophrenia: systematic review and meta-analysis with examination of potential bias. The British Journal of Psychiatry, 204, 20–29. doi:10.1192/bjp.bp.112.116285