On 14 Jul 2005, Christopher D. Green wrote: > > CHICAGO, Illinois (AP) -- New research highlights a frustrating fact about > science: What was good for you yesterday frequently will turn out to be > not so > great tomorrow. > > The sobering conclusion came in a review of major studies published in three > influential medical journals between 1990 and 2003, including 45 highly > publicized studies that initially claimed a drug or other treatment worked. > > > STUDIES REVIEWED > Examples of studies later refuted or watered down by subsequent research, > according to a report in Wednesday's Journal of the American Medical > Association: > > --Hormone pills protect menopausal women from heart disease. A larger, more > rigorous Women's Health Initiative study later found the pills increase > actually heart disease risks. > > --Vitamin E pills protect against heart disease. A more rigorous study found > no such protection. > > --Antibody treatment targeting a bacterial poison improves patients' chances > of surviving sepsis, a potentially deadly bloodstream infection. A much > larger > study found no protection.
>-Antibody treatment targeting a bacterial poison improves patients' > chances of surviving sepsis, a potentially deadly bloodstream > infection. A much larger study found no protection. Well, you get the idea. I haven't had time to read the study (always advised before commenting, but what the heck, this is a discussion list). But I suspect that the problem isn't caused by the studies being too small (because in most of the cases above, "larger studies" fail to find). Logically, if you find a statistically reliable effect with a small study, it should be a walk in the park to replicate it with a larger study. No, I don't think that's it. My suggestion is that the problem lies with the original work being correlational and the later work randomized. Note that for one of the studies, the claim is for a "more rigorous" study. It's dismaying how the literature (medical and psychological) is stuffed with studies drawing causal conclusions from correlational data. Oh, they usually bury a disclaimer somewhere in their paper, but that's not what they emphasize in their conclusions and that's not what they say when they talk to the press. Consequently, the chickens come home to roost when a randomized study is done. Stephen ___________________________________________________ Stephen L. Black, Ph.D. tel: (819) 822-9600 ext 2470 Department of Psychology fax: (819) 822-9661 Bishop's University e-mail: [EMAIL PROTECTED] Lennoxville, QC J1M 1Z7 Canada Dept web page at http://www.ubishops.ca/ccc/div/soc/psy TIPS discussion list for psychology teachers at http://faculty.frostburg.edu/psyc/southerly/tips/index.htm _______________________________________________ --- You are currently subscribed to tips as: archive@jab.org To unsubscribe send a blank email to [EMAIL PROTECTED]
