Hi Robert do you mind if I add you to our China Study email list? I think I have your addy. addressing this is one of the projects some us are going to be working on. if you're interested it'd be great to have you involved.
I've found Ned to be quite professional and I think his analytical skills are solid. He also seems to have an understanding of context. His U-shaped dose-response curve (in the 2nd post) between total cholesterol, in contrast to what Denise insinuates on her own blog regarding Ned's findings, does not discredit Campbell in any way. (By the way, Ned does not suggest that it discredits Campbell.) Campbell was working from a particular model of colorectal cancer based on prior studies, and therefore hypothesized that there would be an upward trend, rather than a U-shaped one. So it is likely it was simply innocently missed. After all, there are hundreds of thousands of combinations of variables (and far more than this if you consider univariable, multivariable, and multivariate analyses!!) in the China Survey data; do we really expect that an exhaustive analysis of every conceivable combination and permutation should have been done by a single team of researchers?
hi ned, i continue to find your posts to be interesting and professionally presented. a few thoughts...
1. one thing i find challenging in all of this is that we're talking about colorectal cancer *mortality* rather than incidence. and the two are not necessarily directly related; there are other factors related to mortality that do not play a role in incidence (eg. treatment). this of course, applies to anyone undertaking an analysis of the china survey data. therefore, i find it difficult to draw conclusions approaching causality because we're not talking about risk of developing the disease.
2. the mortality rates are for 1975-1977 whereas the exposures were collected in 1983, so there is an even greater issue of temporality than we might normally have in a cross-sectional survey.
3. it is possible - especially since we're using mortality as the outcome - that the u-shaped curve actually reflects some other variable (eg. BMI) that might be subject to some reverse causality.
4. have you considered redoing your analyses using the online data? there are some differences between what denise has posted and what is online (denise was forthright about this). it would also be interesting to see the results for 1989 data, as the chinese population may have started to acquire more 'western' dietary patterns by then.
this is an extensive and precise analysis of the minger criticism of tcs. specifically it presents and substantiates the following 3 areas:
1) The author does not appear to be familiar with many of the objectives, content and key concepts presented in TCS. The intent, message and implications of the book are misrepresented to her readers and strawman arguments abound.
2) In spite of claiming to maintain neutrality, the author shows an unmistakable bias in favor of animal foods in her analysis.
3) As a result of this (and lack of experience in the field of epidemiology) much of the data examined and analyzed by the author is misused and/or misinterpreted.
the writing is detailed as well as lucid and well-worth the reading!
i don't know if this is the right place to post this, but a friend sent me this link, an interview w/minger about veganism and her critique. it seems clear she has an axe to grind- the site allows comments, maybe we can post some of the material showing her errors in the critique?
good idea, jenna!
i've mentioned your idea to some people.
if you'd like to start it off, by all means do so, though you'd probably want to start a new thread (since this should be kept for news items) within the group and we can link to it from here.