What does the new Tamiflu data really tell us?

Influenza Treatment, Adolescent
Does Tamiflu have any meaningful effects on the prevention or treatment of influenza? Considering the drug’s been on the market for almost 15 years, and is widely used, you should expect this question has been answered after 15 flu seasons. Answering this question from a science-based perspective requires three steps: Consider prior probability, be systematic in the approach, and get all the data. It’s the third step that’s been (until now) impossible with Tamiflu: Some data was unpublished. In general, there’s good evidence to show that negative studies are less likely to be published than positive studies. Unless unpublished studies are included, systematic reviews are more likely to miss negative data, which means there’s the risk of bias in favor of an intervention.

The absence of a full data set on Tamiflu (oseltamivir) and the other neuraminidase inhibitor Relenza (zanamivir) became a rallying point for BMJ and the AllTrials campaign, which seeks to enhance the transparency and accessibility of clinical trials data by challenging trial investigators to make all evidence freely available. (Reforming and enhancing access to trial data was one of the most essential changes recommended by Ben Goldacre in his book, Bad Pharma.) In 2009, Tamiflu’s manufacturer, Hoffman-La Roche committed to making the Tamiflu data set available to investigators. Now after four years of back-and-forth between BMJ, investigators, and Roche, the full clinical trials data set has been made freely available. An updated systematic review was published today in BMJ (formerly The British Medical Journal), entitled “Oseltamivir for influenza in adults and children: systematic review of clinical study reports and summary of regulatory comments.” This will be a short post covering the highlights. As the entire study and accompanying data are freely available, I’ll await continued discussion in the comments. Continue reading

False “Balance” and an Appeal to Nature in the Globe and Mail

Science vs. BS

One of the encouraging shifts I’ve seen in health journalism over the past few years is the growing recognition that antivaccine sentiment is antiscientific at its core, and doesn’t justify false “balance” in the media. There’s no reason to give credibility to the antivaccine argument when their positions are built on a selection of discredited and debunked tropes. This move away from false balance and towards a more accurate reflection of the evidence seems to have started with the decline and disgrace of Andrew Wakefield and his MMR fraud. And there is now no question that antivaccine sentiment has a body count: Simply look at the resurgence of preventable communicable disease. Today, antivaccinationists are increasingly recognized for what they are – threats to public health. It seems less common today (versus just 5 years ago) that strident antivaccine voices are given either air time or credibility in the media.

But false balance on topics like influenza can occur without giving a voice to groups like antivaccinationists. A more subtle technique to shift perceptions is both widespread and hard to detect, unless you’re aware of it: the naturalistic fallacy, known more accurately as the appeal to nature. In short, it means “It’s natural so it’s good” with the converse being “unnatural is bad.” In general, the term “natural” has a positive perception, so calling a product (or a health intervention) “natural” is implying goodness. The appeal to nature is so common that you may not even recognize it as a logical fallacy. Unnatural can be good, and natural can be bad: Eyeglasses are unnatural. And cyanide is natural. Natural doesn’t mean safe or effective. But the appeal to nature is powerful, and it’s even persuasive to governments. If we believe that health interventions and treatments should be evaluated on their merits, rather than whether or not they’re “natural”, then decisions to regulate “natural” products differently than the “unnatural” ones (like drugs) makes little sense. Yet the Dietary Supplement Health and Education Act was a legislative appeal to nature, introducing a different regulatory and safety standard for a group of products while drawing a fallacious distinction with “unnatural” products like drugs. Canada fell for the appeal to nature too: It has the Natural Health Products Regulations which entrenched a lowered bar for efficacy and safety for anything a manufacturer can demonstrate is somehow “natural”. Continue reading

Echinacea for Colds and the Flu

From flickr user tranchis

There's no persuasive evidence Flu Shield, or other echinacea products, can prevents colds or the flu, or lessen their symptoms or severity.

Colds and the flu (influenza) are among the most frequent and universal illnesses we all experience. Yet we don’t have any truly effective treatments for them. Sure, there are plenty of products available to treat the symptoms. And there are vaccines and some prescription treatments for influenza, which have modest effects.  But it would be nice if there was something that reliably protected us from getting sick at all, or could speed up recovery if we catch something.

We all have our own approaches for dealing with colds. Given that most infections are mild, differ in their symptoms, and will generally resolve on their own, it’s difficult to distinguish if any treatment is actually doing anything. Sure we felt better, but did the Tylenol take the headache away, or did it go away on its own? Would you have coughed as much if you didn’t take that cough suppressant? And did that chicken soup really make the cold go away sooner? Continue reading

Canadian Flu Update 2010

We’re entering flu (influenza) season in North American and the annual vaccination campaigns have started. Here in Canada we’re fortunate to have a health system that covers the cost of immunizations for residents. In Ontario, where I’m located, the province funds a universal immunization program: everyone is eligible for a free flu shot. Here’s some background on influenza and some common questions (and answers) about the flu shot. This information is based on Canadian data and Canadian information with some general information pulled from the CDC. Apologies to SBP’s international readers, as much of this information will not be applicable outside Canada.

If you have any questions that aren’t answered here, please post them in the comments.

What is Influenza?

Influenza is a respiratory illness caused by influenza viruses. It typically appears 1-4 days after the initial infection, with fever, chills, muscle aches and fatigue common. Cough, sore throat and runny nose are also seen. In children, stomach complaints are frequent. On its own, the flu can be nasty. But it can complicate into viral pneumonia, or lead to a subsequent bacterial pneumonia. And if you have other chronic illnesses, like heart failure or asthma, it can cause significant worsening of these conditions. Continue reading

H1N1 Antivax Paranoia

All my illusions that Canada is free of anti-vaccination zealots (antivaxxers) disappeared this week as the H1N1 vaccine was approved in Canada. After starting an H1N1 information page on Facebook (please join) it’s been an ongoing challenge to respond to the antivaccine comments – comments that are incorrect and often deliberately misleading. This is quite time consuming, so my schedule for posts on this blog has been delayed.

I’ve also been blogging at the new SkepticNorth blog on topics that aren’t purely pharmacy related. This week I blogged about the role of naturopaths in the Canadian healthcare system, as well as quackery on campus (U of T, I’m looking at you). So please check out those posts. And please follow the SkepticNorth blog – I’m one of a number of bloggers covering Canadian topics. We appreciate your support.

Back to H1N1, here’s a few credible resources that I highly recommend you consult. If you are a science-based health professional, I’m asking you to roll up your sleeves…get the vaccine, and then help correct the misinformation that’s spreading on the web.

Blogs to follow:

Science-Based Medicine – superb posts, virtually every anti-vax argument is debunked here

Effect Measure - blog written by public health scientists, covers the reality of the pandemic in detail

Other important resources:

Public Health Agency of Canada – for Canadian info, including weekly H1N1 updates

Centers for Disease Control – the American source of H1N1 information

Canadian Immunization Guidelines – outlines in detail the rationale for vaccines, the safety monitoring process, and more.

Consumer Reports Swine Flu Information page – details the variety of swine flu scams out there

Public Health Agency of Canada’s Guidance on the H1N1 Vaccine – for health professionals, details the proper use of the Canadian vaccine.

War on Science – A fantastic series that appeared in Wired magazine that details how anti-science, anti-vaccine sentiment is hurting us all.

I’m asking all of you to speak up for science and reason. Address antivaccination comments and emails with redirection to reputable sources of information. Don’t forward paranoid emails about swine flu or the vaccine. Don’t recommend ineffective or unproven therapies. Call out fearmongering when you see it. This is going to be a long flu season – let’s fight it with science, not paranoia.

Cold-fX: More Hype than Hope for Colds and the Flu

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Cold and flu season is in full swing here in Canada, and we’re all trying to avoid catching something, and recover faster if we’re already sick. Supported by endorsements from Canadian celebrities, and a recently announced tie-in with the 2010 Vancouver Olympics, the biggest selling cold product in Canada is Cold-fX, manufactured by Edmonton-based Afexa Life Sciences. If it’s not already in a pharmacy near you, it will be soon.

What is Cold-fX?

American ginseng (Panax quinquefolium) has been used medicinally for centuries, most commonly as an “adaptogen” where it was and is still believed to be effective for everything from anemia to AIDS to impotence and even cancer. [1] Few uses have been evaluated scientifically, and when studied, ginseng has not been demonstrated to be conclusively effective for any medicinal use. [1] [2]

Colds can be caused by one of hundreds of viruses. In general, adults get 4-6 colds per year.  There are few effective treatments for colds, with most products simply relieving symptoms, without affecting the duration of the cold. Influenza (the flu) is caused by one of three influenza viruses (A, B, or C). Influenza can cause much more serious infections than colds, especially in the very young, the very old, and other high-risk individuals.  Both colds and flu are easily transmitted by hand contact or by inhalation. Both cause a cascade of immune reactions in response to an infection.  Headache, fever, fatigue, congestion, cough, and sore throat are all common symptoms.

Continue reading