Wednesday, December 4, 2013

Half of All Trials Unpublished*

(*For certain possibly nonstandard uses of the word "unpublished")

This is an odd little study. Instead of looking at registered trials and following them through to publication, this study starts with a random sample of phase 3 and 4 drug trials that already had results posted on ClinicalTrials.gov - so in one, very obvious sense, none of the trials in this study went unpublished.

Timing and Completeness of Trial Results Posted at ClinicalTrials.gov and Published in Journals
Carolina Riveros, Agnes Dechartres, Elodie Perrodeau, Romana Haneef, Isabelle Boutron, Philippe Ravaud



But here the authors are concerned with publication in medical journals, and they were only able to locate journal articles covering about half (297/594) of trials with registered results. 

It's hard to know what to make of these results, exactly. Some of the "missing" trials may be published in the future (a possibility the authors acknowledge), some may have been rejected by one or more journals (FDAAA requires posting the results to ClinicalTrials.gov, but it certainly doesn't require journals to accept trial reports), and some may be pre-FDAAA trials that sponsors have retroactively added to ClinicalTrials.gov even though development on the drug has ceased.

It would have been helpful had the authors reported journal publication rates stratified by the year the trials completed - this would have at least given us some hints regarding the above. More than anything I still find it absolutely bizarre that in a study this small, the entire dataset is not published for review.

One potential concern is the search methodology used by the authors to match posted and published trials. If the easy routes (link to article already provided in ClinicalTrials.gov, or NCT number found in a PubMed search) failed, a manual search was performed:
The articles identified through the search had to match the corresponding trial in terms of the information registered at ClinicalTrials.gov (i.e., same objective, same sample size, same primary outcome, same location, same responsible party, same trial phase, and same sponsor) and had to present results for the primary outcome. 
So it appears that a reviewed had to score the journal article as an exact match on 8 criteria in order for the trial to be considered the same. That could easily lead to exclusion of journal articles on the basis of very insubstantial differences. The authors provide no detail on this; and again, that would be easy to verify if the study dataset was published. 

The reason I harp on this, and worry about the matching methodology, is that two of the authors of this study were also involved in a methodologically opaque and flawed study about clinical trial results posted in the JCO. In that study, as well, the authors appeared to use an incorrect methodology to identify published clinical trials. When I pointed the issues out, the corresponding author merely reiterated what was already (insufficiently) in the paper's Methodology section.

I find it strange beyond belief, and more than a little hypocritical, that researchers would use a public, taxpayer-funded database as the basis of their studies, and yet refuse to provide their data for public review. There are no technological or logistical issues preventing this kind of sharing, and there is an obvious ethical point in favor of transparency.

But if the authors are reasonably close to correct in their results, I'm not sure what to make of this study. 

The Nature article covering this study contend that
[T]he [ClinicalTrials.gov] database was never meant to replace journal publications, which often contain longer descriptions of methods and results and are the basis for big reviews of research on a given drug.
I suppose that some journal articles have better methodology sections, although this is far from universally true (and, like this study here, these methods are often quite opaquely described and don't support replication). As for results, I don't believe that's the case. In this study, the opposite was true: ClinicalTrial.gov results were generally more complete than journal results. And I have no idea why the registry wouldn't surpass journals as a more reliable and complete source of information for "big reviews".

Perhaps it is a function of my love of getting my hands dirty digging into the data, but if we are witnessing a turning point where journal articles take a distant back seat to the ClinicalTrials.gov registry, I'm enthused. ClinicalTrials.gov is public, free, and contains structured data; journal articles are expensive, unparsable, and generally written in painfully unclear language. To me, there's really no contest. 

ResearchBlogging.org Carolina Riveros, Agnes Dechartres, Elodie Perrodeau, Romana Haneef, Isabelle Boutron, & Philippe Ravaud (2013). Timing and Completeness of Trial Results Posted at ClinicalTrials.gov and Published in Journals PLoS Medicine DOI: 10.1371/journal.pmed.1001566

Wednesday, September 25, 2013

Brave New Biopharm Blogging

Although a few articles on this site are older, I really only began blogging in earnest about 15 months ago. However, I suppose that's long enough that I can count myself as at least somewhat established, and take a moment to welcome and encourage some interesting newcomers to the scene.
 
Bloggers in dank basements their natural habitat.
There are 3 relative newcomers that I've found really interesting, all with very different perspectives on drug development and clinical research:


The Big Pharma insider.
With the exception of John LaMattina (the former Pfizer exec who regularly provides seriously thought provoking ideas over on Forbes), I don’t know of anyone from the ranks of Big Pharma who writes both consistently and well. Which is a shame, given how many major past, current, and future therapies pass through those halls.

Enter Frank David, the Director of Strategy at AstraZeneca's Oncology Innovative Medicines unit. Frank started his Pharmagellan blog this April, and has been putting out a couple thoughtful perspective pieces a month since then.

Frank also gets my vote for most under-followed Twitter account in the industry, as he’s putting out a steady stream of interesting material.


Getting trials done.
Clinical operations – the actual execution of the clinical trials we all talk about – is seriously underrepresented in the blogosphere. There are a number of industry blogs, but none that aren’t trying first and foremost to sell you something.

I met Nadia Bracken on my last trip out to the San Francisco bay area. To say Nadia is driven is to make a rather silly understatement. Nadia is driven. She thinks fast and she talks fast. ClinOps Toolkit is a blog (or resource? or community?) that is still very much in development, but I think it holds a tremendous amount of potential. People working in ClinOps should be embracing her, and those of us who depend on operations teams getting the job done should keep a close eye on the website.


Watching the money.
I am not a stock trader. I am a data person, and data says trust big sample sizes. And, honestly, I just don't have the time.

But that doesn't stop me from realizing that a lot of great insight about drug development – especially when it concerns small biotechs – is coming from the investment community. So I tend to follow a number of financial writers, as I've found that they do a much better job of digging through the hype than can ever be expected of the mainstream media.

One stock writer who I've been following for a while is Andrew Goodwin, who maintains the Biotech Due Diligence website and blog. Andrew clearly has a great grasp on a number of topics, so when he described a new blog as a “must-have addition” to one's reading list, I had to take a look.

And the brand-new-this-month blog, by David Sable at Special Situations Fund, does seem like a great read. David looks both at the corporate dynamics and scientific stories of biotechs with a firmly skeptical view. I know most blogs this new will not be around 6 months from now (and David admits as much in his opening post), but I’m hoping this one lasts.

. . . . .

So, I encourage you to take a look at the above 3 blogs. I'm happy to see more and diverse perspectives on the drug development process starting to emerge, and hope that all 3 of these authors stick around for quite a while – we need their ideas.



[Bloggerhole photo courtesy of Flikr user second_mouse.]

Thursday, September 19, 2013

Questionable Enrollment Math(s) - the Authors Respond

The authors of the study I blogged about on Monday were kind enough to post a lengthy comment, responding in part to some of the issues I raised. I thought their response was interesting, and so reprint it in its entirety below, interjecting my own reactions as well.

There were a number of points you made in your blog and the title of questionable maths was what caught our eye and so we reply on facts and provide context.

Firstly, this is a UK study where the vast majority of UK clinical trials take place in the NHS. It is about patient involvement in mental health studies - an area where recruitment is difficult because of stigma and discrimination.

I agree, in hindsight, that I should have titled the piece “questionable maths” rather than my Americanized “questionable math”. Otherwise, I think this is fine, although I’m not sure that anything here differs from my post.

1. Tripling of studies - You dispute NIHR figures recorded on a national database and support your claim with a lone anecdote - hardly data that provides confidence. The reason we can improve recruitment is that NIHR has a Clinical Research Network which provides extra staff, within the NHS, to support high quality clinical studies and has improved recruitment success.

To be clear, I did not “dispute” the figures so much as I expressed sincere doubt that those figures correspond with an actual increase in actual patients consenting to participate in actual UK studies. The anecdote explains why I am skeptical – it's a bit like I've been told there was a magnitude 8 earthquake in Chicago, but neither I nor any of my neighbors felt anything. There are many reasons why reported numbers can increase in the absence of an actual increase. It’s worth noting that my lack of confidence in the NIHR's claims appears to be shared by the 2 UK-based experts quoted by Applied Clinical Trials in the article I linked to.

2. Large database: We have the largest database of detailed study information and patient involvement data - I have trawled the world for a bigger one and NIMH say there certainly isn't one in the USA. This means few places where patient impact can actually be measured
3. Number of studies: The database has 374 studies which showed among other results that service user involvement increased over time probably following changes by funders e.g. NIHR requests information in the grant proposal on how service users have been and will be involved - one of the few national funders to take this issue seriously.

As far as I can tell, neither of these points is in dispute.

4. Analysis of patient involvement involves the 124 studies that have completed. You cannot analyse recruitment success unless then.

I agree you cannot analyze recruitment success in studies that have not yet completed. My objection is that in both the KCL press release and the NIHR-authored Guardian article, the only number mentioned in 374, and references to the recruitment success findings came immediately after references to that number. For example:

Published in the British Journal of Psychiatry, the researchers analysed 374 studies registered with the Mental Health Research Network (MHRN).
Studies which included collaboration with service users in designing or running the trial were 1.63 times more likely to recruit to target than studies which only consulted service users.  Studies which involved more partnerships - a higher level of Patient and Public Involvement (PPI) - were 4.12 times more likely to recruit to target.

The above quote clearly implies that the recruitment conclusions were based on an analysis of 374 studies – a sample 3 times larger than the sample actually used. I find this disheartening.

The complexity measure was developed following a Delphi exercise with clinicians, clinical academics and study delivery staff to include variables likely to be barriers to recruitment. It predicts delivery difficulty (meeting recruitment & delivery staff time). But of course you know all that as it was in the paper.

Yes, I did know this, and yes, I know it because it was in the paper. In fact, that’s all I know about this measure, which is what led me to characterize it as “arbitrary and undocumented”. To believe that all aspects of protocol complexity that might negatively affect enrollment have been adequately captured and weighted in a single 17-point scale requires a leap of faith that I am not, at the moment, able to make. The extraordinary claim that all complexity issues have been accounted for in this model requires extraordinary evidence, and “we conducted a Delphi exercise” does not suffice.  

6. All studies funded by NIHR partners were included – we only excluded studies funded without peer review, not won competitively. For the involvement analysis we excluded industry studies because of not being able to contact end users and where inclusion compromised our analysis reliability due to small group sizes.

It’s only that last bit I was concerned about. Specifically, the 11 studies that were excluded due to being in “clinical groups” that were too small, despite the fact that “clinical groups” appear to have been excluded as non-significant from the final model of recruitment success.

(Also: am I being whooshed here? In a discussion of "questionable math" the authors' enumeration goes from 4 to 6. I’m going to take the miscounting here as a sly attempt to see if I’m paying attention...)

I am sure you are aware of the high standing of the journal and its robust peer review. We understand that our results must withstand the scrutiny of other scientists but many of your comments were unwarranted. This is the first in the world to investigate patient involvement impact. No other databases apart from the one held by the NIHR Mental Health Research Network is available to test – we only wish they were.

I hope we can agree that peer review – no matter how "high standing" the journal – is not a shield against concern and criticism. Despite the length of your response, I’m still at a loss as to which of my comments specifically were unwarranted.

In fact, I feel that I noted very clearly that my concerns about the study’s limitations were minuscule compared to my concerns about the extremely inaccurate way that the study has been publicized by the authors, KCL, and the NIHR. Even if I conceded every possible criticism of the study itself, there remains the fact that in public statements, you
  1. Misstated an odds ratio of 4 as “4 times more likely to”
  2. Overstated the recruitment success findings as being based on a sample 3 times larger than it actually was
  3. Re-interpreted, without reservation, a statistical association as a causal relationship
  4. Misstated the difference between the patient involvement categories as being a matter of merely “involving just one or two patients in the study team”
And you did these consistently and repeatedly – in Dr Wykes's blog post, in the KCL press release, and in the NIHR-written Guardian article.

To use the analogy from my previous post: if a pharmaceutical company had committed these acts in public statements about a new drug, public criticism would have been loud and swift.

Your comment on the media coverage of odds ratios is an issue that scientists need to overcome (there is even a section in Wikipedia).

It's highly unfair to blame "media coverage" for the use of an odds ratio as if it were a relative risk ratio. In fact, the first instance of "4 times more likely" appears in Dr Wykes's own blog post. It's repeated in the KCL press release, so you yourselves appear to have been the source of the error.

You point out the base rate issue but of course in a logistic regression you also take into account all the other variables that may impinge on the outcome prior to assessing the effects of our key variable patient involvement - as we did – and showed that the odds ratio is 4.12 - So no dispute about that. We have followed up our analysis to produce a statement that the public will understand. Using the following equations:
Model predicted recruitment lowest level of involvement exp(2.489-.193*8.8-1.477)/(1+exp(2.489-.193*8.8-1.477))=0.33
Model predicted recruitment highest level of involvement exp(2.489-.193*8.8-1.477+1.415)/(1+exp(2.489-.193*8.8-1.477+1.415)=0.67
For a study of typical complexity without a follow up increasing involvement from the lowest to the highest levels increased recruitment from 33% to 66% i.e. a doubling.

So then, you agree that your prior use of “4 times more likely” was not true? Would you be willing to concede that in more or less direct English?

This is important and is the first time that impact has been shown for patient involvement on the study success.
Luckily in the UK we have a network that now supports clinicians to be involved and a system for ensuring study feasibility.
The addition of patient involvement is the additional bonus that allows recruitment to increase over time and so cutting down the time for treatments to get to patients.

No, and no again. This study shows an association in a model. The gap between that and a causal relationship is far too vast to gloss over in this manner.

In summary, I thank the authors for taking the time to response, but I feel they've overreacted to my concerns about the study, and seriously underreacted to my more important concerns about their public overhyping of the study. 

I believe this study provides useful, though limited, data about the potential relationship between patient engagement and enrollment success. On the other hand, I believe the public positioning of the study by its authors and their institutions has been exaggerated and distorted in clearly unacceptable ways. I would ask the authors to seriously consider issuing public corrections on the 4 points listed above.