Investigating CAM

John Hoffer invokes homeopathy as an example of how medical scientists set a higher bar for proof of efficacy for complementary or alternative medicine (CAM).1 Rather than describing this as a “complication,” it might be better understood as an entirely appropriate response to extraordinary claims of any sort. “Evidence” of effectiveness can be found for any treatment, no matter how arcane. The question is how good the evidence is, in light of well-established scientific principles. In the case of homeopathy, we must ask whether chance and poor experimental design can explain positive results obtained in randomized controlled trials (RCTs) of homeopathy or whether RCTs with negative results (usually done by non-advocates of this type of therapy) but accompanied by a vast and well-established body of scientific evidence are in fact in error.

Hoffer also mentions St. John's wort and glucosamine as therapies of established efficacy. However, although positive RCTs of St. John's wort exist, the most rigorous studies (placebo- controlled and randomized, with proper case definitions and a treatment-responsive population) indicate no benefit.2^,3^,4^,5^,6 Glucosamine enjoys the support of over 14 RCTs,7 but critical reviewers will be concerned about the fact that almost all of these were conducted with funding from purveyors of this compound. Publication bias therefore appears to play a role.

Hoffer's call for funding to be directed to case reports and series on CAM therapies as a way of “grooming” them as candidates for RCTs may simply result in a situation in which nothing new is learned. Why? Because uncontrolled and nonrandomized trials are poorly suited for investigating the subjective or “soft” outcomes that CAM therapies so often promise to deliver. Randomization, placebo control and blinding limit the effect of precisely those biases that are likely to explain the “effects” of CAM therapies.

A brief glance through PubMed reveals a plethora of clinical CAM trials. The fact that so many have been done (over 2000 in the case of acupuncture) without producing any clear examples of valid new therapies not only indicates that research money is available but also that it might be better directed.

Why the evaluation of scientifically implausible therapies should be a priority of any magnitude remains an open question. One could argue that some funds should be spent to ensure that prevalent therapies be investigated for safety and drug interactions. Yet research funds are scarce as it is, and the public would be poorly served if money were deliberately funnelled into treatments already recognized as implausible.

Lloyd B. Oppel Physician University of British Columbia Hospital Vancouver, BC