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I believe that there is a point that both of you are missing. The studies of concern are those where an experimental drug is surgically implanted into the brain to treat PD. To meet the "gold standard" of a double-blind, placebo-controlled trial, some investigators believe that a sham procedure is necessary. Unfortunately, sham surgery is not without risks to the patient. The comparison to amputations to prevent the spread of gangrene is inappropriate. In that case, amputation is a medical procedure. We have to rely upon the knowledge and experience of the clinical professional as to whether it is necessary. This is the practice of medicine, not developing an experimental drug. It's also not as simple as not telling the clinical evaluator whether the patient has received surgical treatment or not. That would be obvious to him on a physical examination, as well as to the patient. Reliance on "historical controls" or a "best treatment" group as a control group is permitted, but subject to challenge on the grounds that selection is not randomized. I agree that the practice of medicine does not require well-designed experiments. However, the development of safe and effective drugs does require appropriate testing. There are certainly alternatives to double-blind, placebo-controlled trials, but the large pharmaceutical manufacturers may be reluctant to use them. Consider that the cost of bringing a new drug to market runs into the hundreds of millions of dollars. Do we really want to go back to the unregulated days of pharmaceutical marketing that were filled with unsubstantiated claims of great benefits? These led to the quack remedies that were common in the early 1900's, and have now largely disappeared from our pharmacies. As one of the Pipeliners who developed the survey, I want to encourage patient participation in clinical trials. At the same time, I want any clinical trial participant to be fully aware of all the risks and ethical questions associated with the trial. To be sure, there are options to sham surgery. But, if sham surgery is truly essential in a clinical trial, we must be aware that it's not like a sugar pill placebo, and the patient must demand to know of all the risks. Wilson DeCamp Leesburg, VA In a message dated 9/16/2007 2:03:18 A.M. Eastern Daylight Time, [log in to unmask] writes: arnie, sham surgery is not the only option. consider amputations and gangrene; do we need to do sham surgery to test whether amputations actually prevent the spread of gangrene? if the concern is really that investigators have bias, there are much more ethical approaches than sham surgery. for instance, simply don't tell the clinician evaluating patient condition which patients have received surgery and which haven't. if the concern is about a placebo effect on patients, comparison to historical placebo effects in PD patients seems like a fairly good first cut. statistically speaking, other approaches may not be as pure, but the whole point of medicine is to treat people, not perform elegant experiments. if the trials for something like DBS, just make that information available to the patients and physicians considering the treatment with language along the lines of "40% of PD patients showed improvement with DBS surgery, but there was no control group for ethical reasons. historically, 15% of patients with similar circumstances have shown improvement without any treatment." On 9/14/07, Arnie Kuzmack <[log in to unmask]> wrote: > > There were several comments made by respondents (most of whom are apparently on > this list), that I would like to respond to. > > Comment: The statistical proof is not available in another way. I am no expert > but can't we demonstrate that something is helpful just by a larger sample size > or is a control group always required? Can't we pair people as close as > possible and not have sham? > > Response: A basic principle in statistics is that a larger sample size does not > correct for bias. For example, in the classic case, if the investigators are > emotionally committed to showing that the treatment works, and if they know > which patients got the new treatment, they will have an unconscious > tendency to evaluate patients in the treated group differently from those in the > controls. This is particularly true with diseases like PD, where the evaluation is not > strictly objective. It is also a problem using "historical controls" or pairing > patients as suggested by the commenter, since the evaluations of the treated > group would be subject to evaluation bias. > > This is separate from the "placebo effect", where patients getting a placebo > actually do better than they would otherwise. > ************************************** See what's new at http://www.aol.com ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn