On Tue, 28 Feb 2006 17:02:06 -0800 Rick Froman wrote: > >My point in including the secondary source was not to comment on the >original research findings but to comment on the spin put on them by the >person quoted by the secondary source.
I admit to not not really understanding what your intent was, which is why I provided a couple of different interpretations of what you have intended to say. The point was unclear. >I am sorry if she was misquoted >but I have nothing against her personally. I used the quote only to make >a point. I don't remember for sure but I don't believe she had any part >in the research being discussed. If I was taking exception to the >results of the study itself, I should have cited the primary source. Dr. Dimilia said that "if it worked for her" then it doesn't matter if it doesn't work in the overall group. One can interpret this as "spin" or the recognition that medications have different effects in different populations, that is, there is a medication by group interaction. Indeed, the combination of glocosamine and chondritin (G+C) was the only effective treatment for people with moderate-to-severe pain from knee osteoarthritis -- even Celebrex didn't "statistically significantly' reduce pain (though one can argue whether a result with p< .06 should be taken as being truly non-significant without a replication on a larger sample; by the same token, the "marginaly significant" result of G+C in the overall group [p< .09] deserves the same opportunity instead of being dismissed as ineffective). >My point was that you are missing the point of nomothetic research Actually, given that we are referring to the post you made before I made any comment, your point couldn't be referring to something that I would say in response to your post. >if you say, "it worked for some and it didn't work for others". It's like >saying if half the sample did worse on the treatment and half the sample >did better (for an overall "no difference" outcome) that that is a great >outcome for half of the group and a bad outcome for the other half. That >would ignore the effects of chance which is what the nomothetic approach >is all about. I'm willing to give you the benefit of the doubt and not assume that you're claiming that all human beings constitute a homogeneous population, free of subgroups whose genetic and/or environmental experiences might moderate their drug response. We know that some groups of individuals may show a response to a particular drug while other groups may show a different pattern of response or no response at all. Although traditional groupings such as male-female, ethnic-racial, etc., might be one way of thinking about these groups/population, the situation is probably much more complicated -- the following abstract provides some indication of this point: Authors Wood AJ. Institution Division of Clinical Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-6602, USA. Title Ethnic differences in drug disposition and response. [Review] [11 refs] Source Therapeutic Drug Monitoring. 20(5):525-6, 1998 Oct. Abstract Interindividual variability in drug response is a well-recognized problem resulting in both undertreatment and overtreatment of individuals receiving similar doses of drugs, with the potential for lack of therapeutic effect and for drug toxicity. The potential that interethnic differences might contribute to such interindividual variability in drug response has recently been recognized. Such interethnic differences in drug response may be due to either altered drug disposition or altered drug sensitivity among races at similar drug concentrations. In turn, such racial differences in drug disposition may be related to genetic or environmental factors, which are often difficult to separate. Perhaps the most extreme version of this situation is represented by the drug "BiDil" which is targeted towards African-Americans. The following is an excerpt from a news article in Nature: |The expected approval in the United States of the first drug targeted to a |specific racial group is sparking debate about the future of 'personalized' |medicine. | |Enthusiasts predict a future in which people are given genetic tests to help |choose the drug to which they will respond best. But some experts worry |about the precedent of accepting race as a crude marker for underlying |biological differences - which could still leave many individuals being treated |with drugs that don't work well for them. | |Last week, an advisory committee to the Food and Drug Administration |(FDA) recommended that BiDil, a drug for congestive heart failure, should |be approved for sale with a label designating African Americans as the |target population. The FDA usually follows the advice of its experts and is |expected to make its decision by 23 June. [Wadman M. Racially targeted drug set for approval. Nature. Vol. 435(7045) (pp 1008-1009), 2005. Date of Publication: 23 JUN 2005] And: Authors Meadows M. Title FDA approves heart drug for black patients. Source FDA Consumer. 39(5):8-9, 2005 Sep-Oct. Abstract The Food and Drug Administration's approval in June 2005 of a heart failure drug aimed at black patients marks the first time that the agency has approved a drug for a specific racial group. When added to standard heart failure therapy, BiDil dramatically reduces death and hospitalization in blacks. The key idea here, however, is that there are different groups of individuals whose metabolism of drugs varies, probably for genetic reasons though not always on such obvious bases as sex or racial group membership. This means that drug levels that seem to work fine for one group (e.g., young white males) might not be appropriate for other groups, either because the other group's metabolism reduces the effects of the drug or increases its effect (i.e., producing an overdose effect). "Personalized drugs" of the future may be able to take into account an individual's specific genetic and biological status and adjust drug dosage appropriately. The "Main Effect of Drug" view is an out-dated perspective which has been replaced by a "Drug-by-Population interaction" perspective". >If 1000 people start to flip coins, after one flip approx. 500 will have >flipped heads. On the next flip it is down to 250. Then 125, 62 or so, >then 31 and about 15 and then about 8 then 4 then 2 then there may be >one person who has flipped heads all 10 times. Instead of believing that >person has the power to flip heads at will, I believe that, given that >situation, one of those thousand people is likely to flip heads 10 times >and it has nothing to do with their head flipping ability (supernatural >or otherwise). By chance, some will seem to do better in any trial. What >we need to be able to do in research is separate chance from the actual >effect. Golly, and here I thought that setting alpha=.05 would mean that such a result would occur only 5% of the time on a purely chance basis. Of course, replication of a pattern of results, such as G+C being beneficial for people with moderate-severe knee pain, would be directly relevant to establishing whether G+C is in fact effective. I won't bother to point out that your argument also holds against the use of Celebrex which, though providing a statistically significant effect in the total sample did not provide a statistically significant effect to people with moderate-to-severe, a group that one might have thought *should* have shown some if not the most benefit from a bona fide "drug" (but watch out for those side effects).. >Of course, there could be individual differences in response to >a treatment and those can be isolated in idiographic research. I'm not exactly sure I understand your usage of "idiographic" in the context of drug evaluation. If an anti-depressant medication is effective in reducing depressive symptoms in women but not in men, is that an "idiographic" result? How about if the drug works for middle-class white women but not for lower-SES women of color? Is there are some definitive reference population that defines what a "true drug response" is and variation from this standard by other groups is "idiographic"? >I would >also expect, if a number of people have such an effect, to see some kind >of noticeable outcome in nomothetic research, too. Do you mean like what the FDA has done for BiDil, namely, targeting its use for African-Americans and, more generally, the "personalized medicine" approach? Perhaps the nomothetic-idiographic framework isn't such a good one in thinking about drug metabolism and response. -Mike Palij [EMAIL PROTECTED] New York University >Rick >Dr. Rick Froman >Professor of Psychology >John Brown University --- You are currently subscribed to tips as: [email protected] To unsubscribe send a blank email to [EMAIL PROTECTED]
