Placebo comparator group selection and use in surgical trials: the ASPIRE project including expert workshop.

BACKGROUND

The use of placebo comparisons for randomised trials assessing the efficacy of surgical interventions is increasingly being considered. However, a placebo control is a complex type of comparison group in the surgical setting and, although powerful, presents many challenges.

OBJECTIVES

To provide a summary of knowledge on placebo controls in surgical trials and to summarise any recommendations for designers, evaluators and funders of placebo-controlled surgical trials.

DESIGN

To carry out a state-of-the-art workshop and produce a corresponding report involving key stakeholders throughout.

SETTING

A workshop to discuss and summarise the existing knowledge and to develop the new guidelines.

RESULTS

To assess what a placebo control entails and to assess the understanding of this tool in the context of surgery is considered, along with when placebo controls in surgery are acceptable (and when they are desirable). We have considered ethics arguments and regulatory requirements, how a placebo control should be designed, how to identify and mitigate risk for participants in these trials, and how such trials should be carried out and interpreted. The use of placebo controls is justified in randomised controlled trials of surgical interventions provided that there is a strong scientific and ethics rationale. Surgical placebos might be most appropriate when there is poor evidence for the efficacy of the procedure and a justified concern that results of a trial would be associated with a high risk of bias, particularly because of the placebo effect.

CONCLUSIONS

The use of placebo controls is justified in randomised controlled trials of surgical interventions provided that there is a strong scientific and ethics rationale. Feasibility work is recommended to optimise the design and implementation of randomised controlled trials. An outline for best practice was produced in the form of the Applying Surgical Placebo in Randomised Evaluations (ASPIRE) guidelines for those considering the use of a placebo control in a surgical randomised controlled trial.

LIMITATIONS

Although the workshop participants involved international members, the majority of participants were from the UK. Therefore, although every attempt was made to make the recommendations applicable to all health systems, the guidelines may, unconsciously, be particularly applicable to clinical practice in the UK NHS.

FUTURE WORK

Future work should evaluate the use of the ASPIRE guidelines in making decisions about the use of a placebo-controlled surgical trial. In addition, further work is required on the appropriate nomenclature to adopt in this space.

FUNDING

Funded by the Medical Research Council UK and the National Institute for Health Research as part of the Medical Research Council-National Institute for Health Research Methodology Research programme.

WHAT WAS THE RESEARCH ABOUT?

One of the best ways to prove that a new medicine really works is to use a scientific test called a ‘placebo-controlled trial’. In this type of test, half of the participants are given a new pill and the other half are given a ‘placebo’, which is a dummy pill (usually a sugar pill) that is made to taste and look the same as the active pill, but has no active ingredients. The results are then compared. Just like medicines, new surgical procedures need to be tested to show that they are safe and benefit patients. Ideally, they would also be tested using the ‘placebo-controlled trial’ approach, but asking patients to have ‘dummy’ surgery is not the same as asking people to take a dummy pill. Placebo surgery raises lots of ethics questions and is controversial. As it is controversial, guidelines are needed to recommend when placebo surgery studies can be used (if at all) and what special considerations need to be taken into account. Our research team was commissioned to develop these guidelines.

WHAT DID WE DO?

We summarised, to the best of our knowledge, all previous research that had used placebo surgery and reviewed all the ethics literature on this topic. We also looked at the latest scientific understanding of how placebos work. We then held a workshop to discuss and summarise the existing knowledge and to develop the new guidelines. This involved an international team of patients, surgeons, researchers, ethicists, psychologists, physiologists and funders. We published the guidelines [i.e. the ASPIRE (Applying Surgical Placebo in Randomised Evaluations) guidelines] in an influential medical journal and also wrote several other publications. This report provides a slightly more detailed version of our findings and recommendations.

WHO WILL THIS HELP?

The guidelines will help researchers and doctors know when, and how, to best design placebo surgery studies in the future.