NEJM: Sham Controls in Medical Device Trials

Rita F. Redberg, M.D.

N Engl J Med 2014; 371:892-893September 4, 2014DOI: 10.1056/NEJMp1406388

(Bold emphasis added by RPE)

The problem:

Only 1% of all medical devices reach the market through the premarket-approval route — the only pathway that requires the submission of clinical data. Research has shown that premarket approvals are often based on data from one small trial that used surrogate end points and included only short-term follow-up.1

RCTs are rarely used:

“Blinded, randomized, controlled trials (RCTs), in which the proposed therapy is compared with a placebo or a “sham” (nontherapeutic) intervention, are common for drugs but rare for medical devices.”

Even complex, RCTs with invasive procedures are possible.

“…double-blind trials of fetal-tissue transplantation for Parkinson’s disease, discussed by Freeman et al. (1999). The sham procedure involved making twist-drill holes in the patient’s forehead and was considered necessary and ethical for determining whether there was an effect of treatment beyond the placebo effect (there was not).”

“Another important lesson on the value of sham controls came from vertebroplasty, a procedure in which bone cement is injected into a fractured vertebra for treatment of a compression fracture. Vertebroplasty became popular in the early 2000s, on the basis of observational studies and a nonrandomized trial. Fueled by position statements from various U.S. radiologic and neurologic surgical societies arguing the benefits of these procedures, the number of vertebroplasties performed in Medicare patients nearly doubled between 2001 and 2005, increasing from 45.0 to 86.8 per 100,000 enrollees.3 In 2009, however, RCTs that included a group assigned to receive a nontherapeutic procedure found that pain relief in the sham-procedure group was no different from that in the group that received the actual procedure.4

Placebo effects are even larger with procedures than with drugs.

“ Researchers at the Institute of Medical Psychology in Munich recently quantified that power for various types of placebo treatments in studies of migraine prophylaxis. They found that 58% of patients had a positive response to sham surgery and 38% had a positive response to sham acupuncture, while only 22% had a positive response to oral pharmacologic placebos.5

Conclusion: More RCTs are needed. But the article does not address the problem that even with RCTs it is hard to change physician practice.

Full article is here.
http://www.nejm.org/doi/full/10.1056/NEJMp1406388?query=TOC

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