Call to improve transparency of trials of non-regulated interventions

Efforts to promote the availability of data from clinical trials have been led predominantly by regulators1 or drug companies2 and tend to focus on regulated interventions—that is, drugs, biologics, and medical devices. By contrast, trials of non-regulated interventions such as diets, exercise programmes, physiotherapy, surgical procedures, behavioural interventions, or complementary medicine have received much less attention.

To determine the benefits and harms of an intervention, randomised trial evidence is needed. These trials should be registered and published in an accurate and unbiased manner. Ideally clinical trial protocols and raw data should be made available to ensure transparency and for further use—for example, in individual patient data meta-analyses. These imperatives are well appreciated for trials of regulated interventions, but practices are lagging for non-regulated interventions.

All of us are likely to experience one or more non-regulated intervention in our lives. Yet many trials in these fields are small, underpowered, and lack quality safeguards such as appropriate randomisation, blinding, or choice of placebo or sham control.3 The results are often spurious. Very large, well conducted, trials on non-regulated interventions are rare, even for common lifestyle interventions such as diet and exercise programmes.4 5 Some trials of non-regulated interventions such as surgical procedures and behavioural interventions have intrinsic difficulties in their conduct,6 7 such as how to standardise the intervention. Non-standardisation leads to more heterogeneity and potential for bias.