Use of placebo controls in the evaluation of surgery: systematic review

Abstract

Objective To investigate whether placebo controls should be used in the evaluation of surgical interventions.Design Systematic review.Data sources We searched Medline, Embase, and the Cochrane Controlled Trials Register from their inception to November 2013.Study selection Randomised clinical trials comparing any surgical intervention with placebo. Surgery was defined as any procedure that both changes the anatomy and requires a skin incision or use of endoscopic techniques.Data extraction Three reviewers (KW, BJFD, IR) independently identified the relevant trials and extracted data on study details, outcomes, and harms from included studies.Results In 39 out of 53 (74%) trials there was improvement in the placebo arm and in 27 (51%) trials the effect of placebo did not differ from that of surgery. In 26 (49%) trials, surgery was superior to placebo but the magnitude of the effect of the surgical intervention over that of the placebo was generally small. Serious adverse events were reported in the placebo arm in 18 trials (34%) and in the surgical arm in 22 trials (41.5%); in four trials authors did not specify in which arm the events occurred. However, in many studies adverse events were unrelated to the intervention or associated with the severity of the condition. The existing placebo controlled trials investigated only less invasive procedures that did not involve laparotomy, thoracotomy, craniotomy, or extensive tissue dissection.Conclusions Placebo controlled trial is a powerful, feasible way of showing the efficacy of surgical procedures. The risks of adverse effects associated with the placebo are small. In half of the studies, the results provide evidence against continued use of the investigated surgical procedures. Without well designed placebo controlled trials of surgery, ineffective treatment may continue unchallenged.

Percutaneous coronary intervention in stable angina (ORBITA): a double-blind, randomised controlled trial

“…However, no evidence of harm to placebo groups was found in a systematic review of placebocontrolled surgical trials. 16 When offering an invasive intervention for symptomatic relief, it is essential to know the true efficacy of the intervention, particularly when the patient could choose to continue conservative treatment instead. Moreover, although PCI has become progressively safer, there remains a complication rate of 1-2%.17…”

Prevalence of Triangular Fibrocartilage Complex Abnormalities Regardless of Symptoms Rise With Age: Systematic Review and Pooled Analysis

“…It has not been clearly established that interventions to address triangular fibrocartilage complex variations are better than the natural history owing to varying surgical outcomes [3] and the absence of sham surgery controlled trials. We know from studies on knee arthritis [18] and other conditions [7,22,27] that the placebo affect associated with surgery is very strong and that surgical interventions with entirely subjective outcomes (eg, pain) require sham surgery controls to be certain of their effectiveness. It is possible that the majority of operative interventions for the triangular fibrocartilage complex are no better than regression to the mean, the natural history of wrist symptoms, or the placebo effect.…”

Lay attitudes toward deception in medicine: Theoretical considerations and empirical evidence

“…We believe these objections are misplaced because performing ineffective surgery, in the belief that it is effective, also exposes patients to risks without benefits. For this reason, trials are necessary (Wartolowska et al 2014). Given that very large numbers of patients can be exposed to risky surgical innovations that have not been evaluated by clinical trials, the potential harm of "business as usual" is significant (Miller 2003).…”