# Chelation therapy reduces cardiovascular events for older patients with diabetes **URL:** \ **Category:** In My Humble Opinion\ **Created:** [November 23, 2013, 5:47am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601 "2013-11-23T05:47:10Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Shmendrik](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@Shmendrik](https://boards.straightdope.com/u/Shmendrik)\ **Post date:** [November 25, 2013, 5:36am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/61 "2013-11-25T05:36:40Z")
> [@deltasigma](#): > > Since you don’t think the chief of cardiology at Miami Mount Sinai is worth a quote, how about these 2 from the article which you also must have over looked. > And now the bullshit quote you want to overlook > So yeah. I’m going to go party with these guys. See ya. 😛 Do you even know what “significantly impacted” means in the first quote? It simply means “there appears to be a difference”. No more, no less. It is not equivalent to common parlance expressions such as “this is incredibly significant” which you used above. ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [November 25, 2013, 5:41am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/62 "2013-11-25T05:41:12Z")
> [@Shmendrik](#): > > Do you even know what “significantly impacted” means in the first quote? It simply means “there appears to be a difference”. No more, no less. It is not equivalent to common parlance expressions such as “this is incredibly significant” which you used above. Indeed there does appear to be a difference. One that has even been quantified no less. :eek: :eek: :eek: ---
**Author:** ![Shmendrik](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@Shmendrik](https://boards.straightdope.com/u/Shmendrik)\ **Post date:** [November 25, 2013, 5:43am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/63 "2013-11-25T05:43:54Z")
[XKCD: Significant](http://xkcd.com/882/) ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [November 25, 2013, 5:45am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/64 "2013-11-25T05:45:21Z")
That’s really inapposite you know, as most of the comments in this thread. Why is it that so many people here try to pretend to know more than they actually do? ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [November 25, 2013, 6:01am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/65 "2013-11-25T06:01:06Z")
> [@DSeid](#): > > [1]Post hoc analysis is not the same as a double blind placebo trial. > > [2]Let’s highlight your quotes a bit differently:Your second is not an experts quote but the article writer. The next is the author of the paper who does not count as a potential critic of it. Yes, Lamas thinks his research is great. News at 11. > > And then the other quote in the article, > > [3]I get that you think this is an amazing finding and will brook no critical analysis of it, believing that our shared skepticism is bullshit. You are welcome to ignore the skepticism that many of the rest of us have regarding the significance of this study. Dance happily. I am, I believe, the closest to believing that it is most likely true. The unfortunate thing being that this “finding” will be used by quacks to justify putting more people at risk and fleecing them of their money when, IMHO, likely donating a pint of blood two or three times a year would do them more good and help others in the process. I personally see no value in drinking to that but YMMV. I think the people you’ll find in the bar with you are those who will be using this to sell their snake oil but hey, have fun! [1]This is getting tiresome. Maybe you fancy yourself some sort of expert but if your claim to expertise in the field is being a practicing physician and that’s it, I’m sorry but I’m just not impressed. And certainly your logic or lack of same has done nothing for me either. If you want to start comparing credentials, I’m game for that. [2]This simply absurd and undermines any credibility you might have had. Since when is the opinion of any scientist on the weight to be given to a result not worth considering? If they value their reputations they will be circumspect in their claims and representations. I guess you haven’t published much huh? [3]blah, blah, blah. Don’t try to make this about stupid ignorant me. Nice try but that’s not the issue here. You’ll have to do much better than that. ---
**Author:** ![Shmendrik](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@Shmendrik](https://boards.straightdope.com/u/Shmendrik)\ **Post date:** [November 25, 2013, 6:03am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/66 "2013-11-25T06:03:48Z")
It’s perfectly appropriate in a discussion of why one should be cautious when reacting to unexpected results in a subgroup of a clinical trial. BTW, you asked earlier about “outside reviewers” who expressed doubts about the study. Here’s one which was published in March 2013 in the same issue of JAMA as the TACT results: [http://jama.jamanetwork.com/article.aspx?articleid=1672219](http://jama.jamanetwork.com/article.aspx?articleid=1672219) ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [November 25, 2013, 6:05am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/67 "2013-11-25T06:05:44Z")
> [@Shmendrik](#): > > It’s perfectly appropriate in a discussion of why one should be cautious when reacting to unexpected results in a subgroup of a clinical trial. > > BTW, you asked earlier about “outside reviewers” who expressed doubts about the study. Here’s one which was published in March 2013 in the same issue of JAMA as the TACT results: > [http://jama.jamanetwork.com/article.aspx?articleid=1672219](http://jama.jamanetwork.com/article.aspx?articleid=1672219) Irrelevant since the revised study didn’t come out until later. This has all been covered already. edit: unless you can point out some flaw that would explain why only diabetics saw a 40-50% drop in cardiovascular events. Then I would love to hear your thoughts. ---
**Author:** ![Shmendrik](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@Shmendrik](https://boards.straightdope.com/u/Shmendrik)\ **Post date:** [November 25, 2013, 6:18am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/68 "2013-11-25T06:18:42Z")
You keep saying 40-50%. Would you mind actually reading the study to see what the confidence intervals in that subgroup are? Hint: It’s not 40-50%. ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [November 25, 2013, 6:21am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/69 "2013-11-25T06:21:54Z")
Hint, why don’t you tell me. I haven’t studied statistics in a while and I don’t feel like wading through a journal article. If you don’t mind sharing your wisdom that is. ---
**Author:** ![Shmendrik](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@Shmendrik](https://boards.straightdope.com/u/Shmendrik)\ **Post date:** [November 25, 2013, 6:27am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/70 "2013-11-25T06:27:31Z")
[http://jama.jamanetwork.com/Mobile/article.aspx?articleid=1672238](http://jama.jamanetwork.com/Mobile/article.aspx?articleid=1672238) It’s in this graph: [http://jama.jamanetwork.com/data/Journals/JAMA/926663/joc130024f3.png](http://jama.jamanetwork.com/data/Journals/JAMA/926663/joc130024f3.png) ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [November 25, 2013, 6:35am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/71 "2013-11-25T06:35:04Z")
That’s nice but that doesn’t mean anything to me as I’m sure you probably realized it would not. Oooooo. Ya got me. Score. Now that we’ve got that out of the way, do you have anything meaningful to contribute? ---
**Author:** ![Shmendrik](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@Shmendrik](https://boards.straightdope.com/u/Shmendrik)\ **Post date:** [November 25, 2013, 6:41am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/72 "2013-11-25T06:41:57Z")
I’ve contributed a link to a lengthy article pointing out many potentially serious flaws in this study. I’m unsure whether you’ve read it or not. ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [November 25, 2013, 6:43am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/73 "2013-11-25T06:43:47Z")
> [@Shmendrik](#): > > I’ve contributed a link to a lengthy article pointing out many potentially serious flaws in this study. I’m unsure whether you’ve read it or not. IOW you have no idea what the significance is either. That’s what I thought. Thanks. 😛 ---
**Author:** ![Shmendrik](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@Shmendrik](https://boards.straightdope.com/u/Shmendrik)\ **Post date:** [November 25, 2013, 6:47am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/74 "2013-11-25T06:47:11Z")
They found a difference of 17-55% in the diabetic group, if that’s what you meant by significance. ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [November 25, 2013, 6:49am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/75 "2013-11-25T06:49:11Z")
> [@Shmendrik](#): > > They found a difference of 17-55% in the diabetic group, if that’s what you meant by significance. It’s broken out by type of cardiovascular event and that’s covered in the OP. Do try to keep up please. ---
**Author:** ![Shmendrik](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@Shmendrik](https://boards.straightdope.com/u/Shmendrik)\ **Post date:** [November 25, 2013, 7:04am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/76 "2013-11-25T07:04:58Z")
We’re not even speaking the same language here. > **[Confidence interval](https://en.m.wikipedia.org/wiki/Confidence_interval)** > > In frequentist statistics, a confidence interval (CI) is a range of estimates for an unknown parameter. A confidence interval is computed at a designated confidence level; the 95% confidence level is most common, but other levels, such as 90% or 99%, are sometimes used. The confidence level represents the long-run proportion of CIs (at the given confidence level) that theoretically contain the true value of the parameter. For example, out of all intervals computed at the 95% level, 95% of t Facto... When one says, for example, “this treatment reduces risk of heart attack in group x by 41%”, in actuality it means something like “we are 95% confident that it reduces risk by 15 to 70%”. You can’t go around trumpeting a reduced risk of 40 to 50% when that’s not even what the results of this possibly flawed study show. ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [November 25, 2013, 7:12am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/77 "2013-11-25T07:12:28Z")
OK fine. So 15 to 70% isn’t significant. Got it. :rolleyes: :rolleyes: :rolleyes: ---
**Author:** ![zweisamkeit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zweisamkeit/32/4360_2.png) [@zweisamkeit](https://boards.straightdope.com/u/zweisamkeit)\ **Post date:** [November 25, 2013, 7:19am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/78 "2013-11-25T07:19:53Z")
> [@deltasigma](#): > > And by all means, continue to characterize my reactions to your apparent prejudices as “temper tantrums.” I get that a lot so I’m used to it. 😛 Maybe you should stop to think about _why_ you “get that a lot.” Sheesh. ---
**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\ **Post date:** [November 25, 2013, 7:28am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/79 "2013-11-25T07:28:01Z")
> [@zweisamkeit](#): > > Maybe you should stop to think about _why_ you “get that a lot.” > > Sheesh. I don’t really care. I love to learn and share what I learn. Some people appreciate that but many don’t for whatever reason. I’ve never been able to figure that out. If I still have some sense of awe and wonder at things like this and that annoys people, too fucking bad. It should serve as reminder of not what a fool I am but how dead and jaded they’ve become. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [November 25, 2013, 11:54am UTC](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601/80 "2013-11-25T11:54:37Z")
As I explained earlier, you simply cannot jump from “percentage change” to “significance level” without further statistical analysis. This is why we usually talk about p values instead of % difference. Again - if, in your control group, you have four heart attacks out of seven thousand people, and in your test group, you have two heart attacks out of seven thousand people, that is a 50% reduction, but is almost certainly not significant - it’s just statistical noise. You need to look at the actual numbers. 50%, or 70%, or 300%, or 1.2% _may_ be significant, or it may not. [Previous page](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601.md?page=3) [Next page](https://boards.straightdope.com/t/chelation-therapy-reduces-cardiovascular-events-for-older-patients-with-diabetes/674601.md?page=5)