posted
So I've been reading up on Qnexa, a new treatment for obesity. It seems interesting although I want to see the actual studies to see how they were designed, what the results were, and what issues there may be.
Only problem is I can't find the studies on Qnexa. Usually, I'm able to find things through Pubmed or the other databases I use - but here I'm flummoxed. The studies should be publicly available somewhere online, no?
Anyone know what I'm missing? And might there be any databases or resources you might recommend? (Personally, I've recently found SIDER Side Effects to be quite useful.)
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posted
You never fully answered my question about suicide risk in adolescents. But you can use clinicaltrials.gov to augment your search as it lists all US clinical trials.
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posted
The point isn't if you can find the numbers, the point is that you're misrepresenting the suicide risk by leaving out the numbers in your analysis in your blog posts. I'm not purchasing a book to see if you know the correct numbers.
I have read the research paper that the black box warning came from. It's part of my training.
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quote:Only problem is I can't find the studies on Qnexa. Usually, I'm able to find things through Pubmed or the other databases I use - but here I'm flummoxed. The studies should be publicly available somewhere online, no?
Did you try searching for the active ingredient, rather than the trade name?
posted
So what numbers would you say represent the risk? If 1,000,000 adolescents take an SSRI medication and 1,000,000 don't, what greater percent will have suicidal ideation based off your knowledge?
Let me know what your number is and I'll find some numbers for you Posts: 3060 | Registered: Nov 2003
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posted
Of course, James, but Qnexa is made of two medications that are used for different things and a search for the two ingredients together did not have any results.
For most meds, there's a generic name that would work.
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posted
Out of a meta analysis of approximately 4000 adolescents, there was an increase in suicidal ideation from 2% to 4% between the placebo group and the group treated with antidepressants. There were no completed suicides in the study and I believe there was no statistical difference in suicide attempts between the two groups. Due to the small number of adolescents in the meta analysis, the difference is statistically significant but the quantity of the difference is uncertain. A more recent article in 2007 by Bridge et al noticed suicidal ideation to be 2% in placebo and 3% in treated groups.
The perceived risk of suicide is far outweighed by the benefit of these medications for depression and anxiety.
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quote:Separate analyses for suicidal ideation and behavior for all the trials and indications yielded similar results, that is, the RR for suicidal ideation was 1.74 (95% CI, 1.06-2.86) and the RR for suicidal behavior was 1.90 (95% CI, 1.00-3.63).
Hammad et al, 2006
The reason suicidal behavior isn't acknowledged to be increased is due to the spread of their numbers. The 95% confidence interval includes 1.00 which points to an inability to assert increased relative risk to placebo. The suicidal ideation is noted to have a relative risk of 1.74 but look at the confidence interval: 1.06 - 2.86. That means that the true relative risk of suicidal ideation between all SSRIs and placebo lies somewhere between 1.06 and 2.86 (at least, 95% likely to lie there). It could be close to 3 times more, or it could be a mere blip at going from 20,000 adolescents out of 1,000,000 adolescents who are depressed on no medication and thinking of how they would like to be dead to 21,200 adolescents out of 1,000,000 adolescents who are depressed on an SSRI and thinking of how they'd like to be dead. But being treated with a medication that has a NNT of approximately 3. So estimate about 300,000 of those adolescents are going to start feeling better in a clinically significant way.
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quote:That means that the true relative risk of suicidal ideation between all SSRIs and placebo lies somewhere between 1.06 and 2.86 (at least, 95% likely to lie there).
Much as I like what you're saying, I think it is important to point out that the 95% confidence interval does not indicate there is a 95% chance the true value lies in it (indeed, you cannot discover such probabilities in a classical framework, such as is applied here). All it says is that, if the null hypothesis were true, there would be a 95% chance we would observe a value in that range. Since the null hypothesis is almost certainly not true (that is, there's probably some effect, however small, varied, or irrelevant), the confidence interval says almost nothing about the range where there would be a 95% probability for the value to fall into.
edit: almost nothing only in the sense that the range could be fairly different. In practical terms, the range will probably be in that vague area.
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posted
Thanks for the correction in the definition of confidence interval. It's a sneaky idea.
How would you more accurately state the worth of the confidence interval 1.06 to 2.86 as compared to, lets say, 4-6?
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posted
Actually, I realized my explanation above is also a bit confused (and I wrote 95% instead of 5%). What it means is, if the true value is not in the confidence interval (say, the 95% confidence interval), then something with a 5% (or less) probability has occurred (modulo the model in question).
A good way to say it is, 95% of the time we apply this procedure (including sampling), the confidence interval will include the true value. But, those intervals might only overlap a little (even if they do include the true value), which would be frequently incompatible with the probability the true value falls in any one of the ranges being 95%. (Indeed, under a frequentist view, you can't talk about the probability of the true value falling anywhere -- the true value exists, it does not have a probability).
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posted
Okay. I see it as a bit of a direction in which it's worded. I see the nuance but that nuance is hard to remember!
So, 95% of the time we attempt to estimate the relative risk of suicidal ideation of SSRI vs placebo use, the confidence interval will include the true value. That means the true value is (for 95% of the times we attempt it) fairly likely to fall within the interval of 1.06-2.86?
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posted
Yes, the true value is quite likely to fall in there (assuming the model, including the sampling model, is correct -- but the model for such trials is generally pretty simple and unobjectionable, such as ANOVA).
Since 95% is an arbitrary and meaningless choice of significance level anyways (though it is important to have such a standard), there's no real need to say anything beyond that it is quite likely.
edit: not that ANOVA doesn't have problems, they just tend to arise when it is applied to more complicated data. Newer multilevel formulations are generally superior in those cases .
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quote: Out of a meta analysis of approximately 4000 adolescents, there was an increase in suicidal ideation from 2% to 4% between the placebo group and the group treated with antidepressants. There were no completed suicides in the study and I believe there was no statistical difference in suicide attempts between the two groups. Due to the small number of adolescents in the meta analysis, the difference is statistically significant but the quantity of the difference is uncertain. A more recent article in 2007 by Bridge et al noticed suicidal ideation to be 2% in placebo and 3% in treated groups.
The perceived risk of suicide is far outweighed by the benefit of these medications for depression and anxiety.
Exactly. The studies have shown that the increase in suicidal ideation ranges from different values but it is a reasonable statement to say that it could double the risk.
In my experience, that number is likely to be underreported. Studies that are run by an organization that has every motive to get certain results tend to be biased in favor of that result.
There are many ways that studies can be manipulated, like under reporting side effects or characterizing certain responses as meaning one thing or another.
I think we can agree on the following: use of antidepressants has been shown to increase the risk of suicidal ideation. We might not agree on this, but I think this is true - there is no direct data to suggest that they reduce suicidal ideation or risk.
The question of whether or not that risk is worth it is a personal evaluation for someone to make with their doctor. In making that decision, it seems reasonable that someone should know that something they're about to take could double their risk of thinking about suicide.
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posted
I think you avoid using numbers that more accurately represent the data. Out of fifty adolescents treated for depression, an additional one person will have thoughts of suicide but the studies did not show an increase in attempt or completed suicide. However, for every 4 (let's err on the side of less than more), one additional person will have their psychiatric symptoms clinically improve (specific amount on depression inventory scales available, I just dont know them offhand).
The above part of informed consent is a great deal more helpful and truthful than "could double their risk of thinking about suicide."
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posted
As someone who has been personally involved in testing these types of vaccinations and medications, I can say without a doubt that you are overestimating the amount of error in studies. Most studies are methodical in the recording of data, and most companies want to know what the actual risks are with each medication.
You assumption that companies deliberately fudge data is unsupportable when you look at the amount of studies done, the amount of medications released each year. Sure, there are occasionally stories about this happening, but they make the news because they are rare.
Your assumptions are flawed, and that affects the way you present the data you collect.
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posted
Phanto, you've demonstrated a persistent negative perception of antidepressants over the years, and a pretty profound ability to ignore any and all data that contradicts your impressions. It's as though your thoughts on the matter are stored in ROM. Given that that's not actually physically possible, I have to--to put it baldly--question your intellectual integrity.
Dabbler, I really appreciate the time that you've spent here trying to stem the tide of minsinformation. I'm glad that we have someone at Hatrack with the combination of professional experience, academic background, and energy necessary to provide an honest, thoughtful examination of Phanto's claims every time he makes them.
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quote:Originally posted by Noemon: Phanto, you've demonstrated a persistent negative perception of antidepressants over the years, and a pretty profound ability to ignore any and all data that contradicts your impressions. It's as though your thoughts on the matter are stored in ROM. Given that that's not actually physically possible, I have to--to put it baldly--question your intellectual integrity.
This.
Phanto, we've been through all of this multiple times. Your response to conflicting information and factual counterpoint, as well as the genuinely non-professional state of your medical information site, all discredit you because they show a desperate adherence to unprofessional personal bias.
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posted
See, the funny thing is that this thread is me asking for help researching a topic completely unrelated to antidepressants.
Antidepressants are a complex issue. I'm willing to admit that I don't know enough about them so have stopped dealing with the issue in general.
I'll say that point-blank: antidepressants are a very complicated issue and I am reevaluating my position on them.
The thing about the pharmaceutical industry is that even treatments which are widely accepted as one thing can, in a moment, be cast into doubt.
The bisphosphonates recently were questioned for possibly causing bone issues(!). A major diabetes drug was shown to be causing large amounts of heart problems. And many more, on a weekly basis, basic tenants of drugs are challenged.
Sometimes you just have to admit that you don't know enough.
Kwea: See, I'd believe that companies want an accurate depiction of the risks from their medications if they behaved in a manner that reflected said concern. From my perspective, I see big Pharma companies routinely fined hundreds of millions of dollars for blatant violation of ethical standards.
Having spent some time digging through research studies and spoken to experts on statistics, I've learned that there are very many ways to get results biased one way or another. Take a study to someone who has spent their life studying biostatistics, and in less than a minute, you'll get 5 valid ways the data could be tweaked.
quote: In response to the lawsuit, Glaxo published the results of nine pediatric clinical trials showing Paxil is mostly ineffective in treating children and may actually increase the risk of suicidal tendencies.
quote: The pharmaceutical giant Pfizer agreed to pay $2.3 billion to settle civil and criminal allegations that it had illegally marketed its painkiller Bextra, which has been withdrawn.
If I had the time, I could come up with 10 more such cases of pharmaceutical companies seemingly choosing to make money by violating ethical standards. Maybe I'm missing something.
quote: Phanto, you've demonstrated a persistent negative perception of antidepressants over the years
Gosh, I think you'd be hard pressed to find me saying anything on the subject before a year from now. Maybe you just feel that it's been that long or maybe you have a better memory than me.
So I just want to know if anyone has suggestions about how to find information about Qnexa =)
posted
Phanto, fair enough. I am not saying that ethical violations don't happen, or that people shouldn't research things they wonder about.
OK, I will give you the ten you claim to have. How many of those types drugs are on the market? How many companies market them? How many doctors and other medical personnel were involved in those studies? How many of them were responsible for "hiding" data? If they have been cited recently, how many of those violations are administrative?
I think the pharm business needs reform, but I don't think that most studies are flase. Most of the fines being leveled these days are for marketing off label uses and for Medicare/Medicaid fraud.
As far as drug warnings changing after release....NO study can ever compare to the data gathered after release. These is no way to test it on that many people and get reliable results. The mere fact that hundreds of thousands of additional people take it means that the source pool of data is larger, and by definition a larger pool of people means a more accurate view of side effects, and a more accurate picture of it's effectiveness. The fact that there are updates actually means that the drug companies, by and large, are doing their jobs by letting the public know about new info.
Honestly, I am glad you are reexamining your views on these types of drugs. They are complex, to be sure, and my main worry about your views was that you were presenting them as fact on your web sited for the public to view. I am not a huge fan of them myself, but I don't see anyone claiming they are magic bullets for every client. But for some patients they are literally a life saver, and I would hate to have someone not try them because of an article like that.
I will see what I can find out about Qnexa if you want, since we poked at you for this again.
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