A new scale that measures the potential harm of invasive research placebos has been successfully tested by anaesthetists.
Forty-three independent clinicians have tested the new scale, with all being asked to measure the risk of harm posed by control group interventions in clinical anaesthesia studies using the Serious Harm and Morbidity (SHAM) scale.
This work builds upon the World Medical Association's Declaration of Helsinki on Ethical Principles for Medical Research Including Human Subjects, which was last published in 2008. The declaration states: "Patients who receive placebo or no treatment will not be subject to any risk of serious or irreversible harm."
However, many studies seem to directly contravene this as they make use of highly invasive placebos. The SHAM scale results, which were first published in Anaesthesia in February 2011, found that there are many clinical studies using highly invasive placebos.
Study leader Dr Allan Cyna, a consultant anaesthetist from the Women's and Children's Hospital in North Adelaide and a Clinical Senior Lecturer at the University of Adelaide said: "More than half of the research papers we looked at for the scale development study, published in 2011, subjected control group patients to risks of moderate or major harm and ill health without apparently considering the use of a less invasive placebo."
The reason the scale was developed was to further the benefits of using placebos in scientific analysis. Sugar pills or saline injections contain no active ingredients, and are therefore a useful tool for researchers. However, when it comes to using placebos for local anaesthetic control, the technique could create risk complications. This could be reduced if a less invasive alternative was to be used, without directly impacting the scientific validity.
SHAM is therefore a useful tool for researchers wanted to measure precisely how invasive these local anaesthetic placebos are. Using a grading system, they can outline any potential complications and less harm.
Co-author and senior registrar Dr James Jarman concludes: "We should be using the least invasive placebo that is consistent with maintaining scientific rigour, so as to make research as safe as possible."