tag:blogger.com,1999:blog-4098620.post8883636808491644126..comments2024-03-15T04:02:42.341-04:00Comments on CrimLaw: I Need Someone to Translate StatisticianeseUnknownnoreply@blogger.comBlogger1125tag:blogger.com,1999:blog-4098620.post-61995992868723949132010-10-25T14:36:59.953-04:002010-10-25T14:36:59.953-04:00It looks like no one actually qualified has answer...It looks like no one actually qualified has answered, so for whatever it's worth...<br /><br />When Reuters says, "Thirty-eight studies showed that exposure to drug company information resulted in more frequent prescriptions, while 13 did not have such an association," I think they are using part of the "Methods and Findings" section in the Abstract: "38 included studies found associations between exposure and higher frequency of prescribing and 13 did not detect an association. Five included studies found evidence for association with higher costs, four found no association," and not the text you quote, which is about publication bias.<br /><br />In a meta-analysis like this one, you have to make sure that the method for choosing studies is unbiased. However, if you base your survey on the published literature, you are implicitly excluding unpublished studies. Since Journals are more likely to publish a paper that finds an effect than one that doesn't, that introduces bias. However, larger and more complicated studies are likely to be published anyway.<br /><br />The authors are saying they found that complex studies which examined more than one effect (multiple units of analysis) found less of an effect on prescribing than simpler studies which examined only one effect. Since the number of effects in the report is an attribute of how the study is written, not of the underlying data, both groups of studies should have similar results. That they did not implies that the simpler studies were subject to greater publication bias, biasing the meta-analysis in favor of finding an effect.<br /><br />I believe the authors are deprecating the single-unit studies out of a desire to be conservative in their conclusions. Five of the authors are associated with Healthy Skepticism, an advocacy group aimed at "Improving health by reducing harm from inappropriate, misleading or unethical marketing of health products or services, especially misleading pharmaceutical promotion." By using only the most conservative data, I think they hope to avoid accusations of bias.<br /><br />I think both news articles overstate the study's conclusions. It seems inconceivable to me that drug marketing has no effect on the frequency, cost, or quality of prescribing. Indeed, the authors of this study found that most studies reported either a bad effect on frequency, cost, or quality, or no effect at all, which seems to imply there really is an effect.<br /><br />However, the authors' conclusion says otherwise: "The limitations of studies reported in the literature mentioned above mean that we are unable to reach any definitive conclusions about the degree to which information from pharmaceutical companies increases, decreases, or has no effect on the frequency, cost, or quality of prescribing." I guess they did the math and decided they couldn't quite get there.<br /><br />Nevertheless, this is good enough for their purposes. They wanted to address drug manufacturers' claims that marketing improves the quality of prescribing by keeping doctors better informed. While they cannot conclusively rule out that possibility, they were not able to detect any improvement in prescribing. Therefore, they conclude that doctors should ignore promotional materials because they don't seem to help.<br /><br />Obviously, I was kind of fascinated by this study, but I could certainly be misreading it, and I'm in no position to say whether their data, methods, or conclusions are scientifically valid or reasonable. I'm just telling you what I got from it.<br /><br />I assume you are looking for a link between drug marketing and drug diversion. My guess is that if you contact the authors through the <a href="http://www.healthyskepticism.org/global/contact/" rel="nofollow">Healthy Skepticism</a> site, they might be willing to give you more information and pointers to good studies since your interests seem to mesh with theirs.Windypundithttps://www.blogger.com/profile/01788171819370012437noreply@blogger.com