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Peter Gill's blog

All Trials Registered | All Results Reported

Peter Gill
Last edited 9th January 2013

“Thousands of clinical trials have not reported their results; some have not even been registered.” All trials registered | All results reported

This is a problem.

A petition was launched today that calls on governments, regulators, and research bodies to put measures in place to register and report the methods and results of clinical trials. This initiative, led by Bad Science, Sense About Science, BMJ, James Lind Initiative and CEBM is important. This issue effects all of us: patients, researchers, clinicians, politicians, scientists, and industry.

The petition was followed with a rip roaring editorial by Iain Chalmers, Paul Glasziou and Fiona Godlee in the BMJ that calls for all trials to be registered and their results published. This excellent piece details the consequences of our collective abstention from action and provides advice to patients whom are invited to participate in clinical trials; name:

“Agree to participate in a clinical trial only if: (1) the study protocol has been registered and made publicly available; (2) the protocol refers to systematic reviews of existing evidence showing that the trial is justified; and (3) you receive a written assurance that the full study results will be published and sent to all participants who indicate that they wish to receive them.”

Don’t wait, sign the petition now.

After signing you can automatically share the message “I've just signed the #AllTrials petition for all trials registered and all results reported” on Twitter or Facebook.

Be proud you are taking a step for transparency and improving patient care. I know I am.

Let’s be honest. Most researchers and clinicians only read the abstracts of research studies. This is true even when they diligently search out and find the original article that inspired a news headline. A cynical colleague suggested that people only read the Tweets of someone that only read the abstract of the article. People are busy and pressed for time; skimming abstracts is an efficient way to stay up-to-date with research findings without onerously sifting through pages of details. People want the bottom line. But this approach inherently relies on journals to ensure accuracy in abstract reporting.

Well, it seems this strategy is problematic for many reasons, particularly because of “spin” or “specific reporting emphasizing the beneficial effect of the experimental treatment.” A recent study in PLoS Medicine sought to quantify this problem: the authors identified two-arm, parallel-group RCTs, searched for associated press releases, and examined both for the presence of “spin.”

What they found was concerning: 47% of press releases and 40% of abstracts contained “spin.” After completing a multivariable analysis, “spin” in the article abstract was the only factor associated with “spin” in the press release (RR, 5.6; CI, 2.8-11.0; P<0.001). Therefore, the major driver of inaccurately reported findings was written by the author. In fact, 31% of press releases misinterpreted the results from the trial, either over- (86%) or under- (14%) estimating the benefit of the therapy.

Press releases are an important part of research dissemination. A study completed earlier this year in the BMJ by Evidence Live Faculty Lisa Schwartz and Steve Woloshin found that high quality press releases by journals can influence media coverage of the associated article. Increased coverage is beneficial if the press release is accurate which relies heavily on the abstract.

People involved in conducting research understand the importance of the abstract. This is the first piece read by a journal editor once submitted, and the decision to peer review largely relies on the authors ability to ‘sell’ their study in 300 words or less. Therefore, there is an incentive for authors to (over) emphasize the main results of the study in a manner that is usually critiqued in the peer review phase. While changes may be made to the full-text article to “dumb down” the authors conclusions, it is unclear how much the abstract changes as a result of peer review.

Realistically, the previously described process is unlikely to change, and everyone is not going to start reading the full-text article, particularly the media. Therefore, the onus is on journals to take an active role to ensure accuracy in abstract reporting and press releases. If they don’t, who will? If you want to learn more about what journals are doing to tackle this problem, come and ask the editors yourself at Evidence Live 2013.

*Note: this blog has also been posted on Evidence Live Blog.

Evidence-based mythbusting - a foray in sports products

Peter Gill
Last edited 19th September 2012

Myths are everywhere. Haunted forests. Greek Gods. You name it and there’s probably a myth for it. But what about myths related to sports? Surely athletes and consumers would not spend millions of dollars per year purchasing sports drinks, protein shakes and energy drinks if they didn’t work?

As outlined in the previous blog post on sports performance products, the CEBM team in Oxford looked at the evidence behind sports products. While completing the systematic assessment of the evidence underpinning claims six claims continually re-emerged.

Rather than use our traditional skills of evidence-based medicine, we experimented with a foray in evidence-based mythbusting (EBMythbusting).

Did your coach ever tell you to drink more fluid if the colour of your urine was dark? If they did, they better have provided you with a “urine colour chart” as athletes are less reliable than trained investigators at distinguishing the colour of their urine. Well if not, consider yourself lucky by having avoided many unnecessary trips to the toilet. The evidence is scarce to suggest that using urine colour is a useful or accurate as a marker of hydration. Best-case scenario is that first morning urine can tell you your hydration status.

Despite sport companies wanting you to believe that “Your brain may know a lot, but it doesn’t know when your body is thirsty. You need to drink during exercise before you feel thirsty in order to get enough fluids in your body to maintain your performance level”, the evidence suggests that drinking before you are thirsty may worsen performance and puts athletes at risk of hyponatraemia (low blood sodium levels). Apparently the human body worked before sports drinks were invented.

Does Red Bull really give you wings? Well the company at least states that “in extensive studies it has been repeatedly proven that Red Bull increases performance”. In reality any caffeine slightly improves performance (not flying), but is this surprising? Why else do we drink coffee in the morning?

Surely if protein and carbohydrate combinations after working out stimulates “increased uptake of glucose by the cells, resulting in faster glycogen storage” then it must improve performance. Unfortunately EBMythbusting has revealed that the effect is inconsistent and probably no better than a well-balanced and nutritious diet. Apparently Mom was right all along.

Pure branch chain amino acids. These just sound like they must work. Apparently they, amongst other things, can “help to sustain a healthy immune system during periods of intense training and play an important role in fatigue and performance”. Maybe, at best, and only to potentially reduce muscle soreness. But isn’t feeling sore after the gym a reminder that you exercised!

Sick of your skin? Do you want a second skin? Well here is the answer for you: “this ultra-tight, second-skin fit delivers a locked-in feel that keeps your muscles fresh and your recovery time fast”. Might as well stick to a massage or hot/icy cold-water therapy as these tend to work just as well to improve recovery.

EBMythbusting has challenged these common sports myths. Maybe practicing evidence-based medicine is really just an exercise in mythbusting. Why don’t you give it a try?

*Note: this blog has also been posted on Evidence Live Blog.

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