Gold mine or dumpster dive? A closer look at adverse event reports

Correlation doesn't always equal causation

All informed health decisions are based on an evaluation of risks and benefits. Nothing is without risk. Drugs can provide an enormous benefit, but they all have the potential to harm. Whether it’s to guide therapy choices or to ensure patients are aware of the risks of their prescription drugs, I spend a lot of time discussing the potential negative consequences of treatments. It’s part of my dialogue with consumers: You cannot have an effect without the possibility of an adverse effect. And even when used in a science-based way, there is always the possibility of a drug causing either predictable or idiosyncratic harm.

An “adverse event” is an undesirable outcome related to the provision of healthcare. It may be a natural consequence of the underlying illness, or it could be related to a treatment provided. The use of the term “event” is deliberate, as it does not imply a cause: it is simply associated with an intervention. The term “adverse reaction,” or more specifically “adverse drug reaction,” is used where a causal relationship is strongly suspected. Not all adverse events can be be causally linked to health interventions. Consequently, many adverse events associated with drug treatments can only be considered “suspected” adverse drug reactions until more information emerges to suggest the relationship is likely to be true.

Correlation fallacies can be hard to identify, even for health professionals. You take a drug (or, say, are given a vaccine). Soon after, some event occurs. Was the event caused by the treatment? It’s one of the most common questions I receive: “Does drug ‘X’ cause reaction ‘Y’?” We know correlation doesn’t equal causation. But we can do better than dismissing the relationship as anecdotal, as it could be real. Consider an adverse event that is a believed to be related to drug therapy: Continue reading

Wobenzym N: A closer look at “systemic” enzyme therapy

One of the recurrent themes in alternative medicine is the practice of simplifying complex medical conditions, and then offering up equally simple solutions which are positioned as still being within the realm of science. This approach allows the practitioner to ignore all of the complexity and difficulty of practicing real medicine, yet offer nostrums that, on first glance, can sound legitimate. Science-y, even.

I’ve discussed this before in non-science-based approaches to food intolerances, whether it’s using clinically useless IgG blood tests, or declaring the universal dietary enemy to be gluten. David Gorski elaborated on the same theme recently at Science-Based Medicine in the context of cancer treatment, contrasting the simplistic views of alternative medicine purveyors with the facts of cancer research. Cancer is stunningly complex – each of the hundreds of different variants of the disease. I’m always amazed when I speak with oncologists about how treatment regimens have been established. They describe how the results of dozens of clinical trials, led by different trial groups around the world have each contributed to establishing the current “best” regimens for each cancer: the appropriate drugs, doses, intervals and treatment intensities. Good evidence speaks all languages, and as new data emerges, practices change quickly to build upon whatever new evidence has emerged. The complexity of treatments continue to increase. Overlay the genetic and genomic complexity David described, and you get a sense of the challenges (and opportunities) cancer researchers face in order for science continue to improve outcomes for patients with cancer.

So it’s a bit of a shock when you shift your attention to the alternative medicine “literature”, where simple solutions abound. One that’s popular among patients I speak with, particularly those with European backgrounds, is the use of what are called systemic enzymes – enzymes, consumed orally, with the intent of whole-body effects. These products are not used as part of “conventional” medicine but are popular supplements recommended by alternative practitioners. I was recently asked about a product called Wobenzym N, a product with German roots which is advertised with the following claims [PDF]: Continue reading

Dilutions of Grandeur: It’s World Homeopathy Awareness Week

Shelf sign: Homeopathy is nonreturnable

Homeopathy is nonreturnable

April 10-16 is World Homeopathy Awareness Week, dedicated by homeopaths to promote an awareness and understanding of homeopathy. I think that’s an excellent idea. Homeopathy is an elaborate placebo system of sugar pills. It doesn’t work. It cannot work.  If it did, physics, biochemistry and pharmacology as pharmacists know it would be false. Of all alternative medicine, homeopathy is the most implausible of them all.  Based on the absurd notion of “like cures like” (which is sympathetic magic, not science), proponents of homeopathy believe that any substance can be an effective remedy if it’s diluted enough: raccoon fur, the sunlight reflecting off Saturn, even pieces of the Berlin Wall are all part of the homeopathic pharmacopeia.  And when I say dilute, I mean dilute. The 30C “potency” is common – it’s a ratio of 10-60.  You would have to give two billion doses per second, to six billion people, for 4 billion years, to deliver a single molecule of the original material. So remedies are effectively and mathematically inert – they are pure placebo. Not surprisingly, there is no persuasive medical evidence that these products have therapeutic effects.

Homeopathy could be written off as a harmless nostrum if it caused no harm. But that’s not the case. Homeopathy can delay patients from seeking science-based treatments. Consumers buy products thinking they are effective, when they have no active ingredients. When they’re on pharmacy shelves, it’s unfair and unethical to expect patients to be able to able to distinguish real drugs from placebos.  A paper from Michael Baum and Edzard Ernst, writing in the American Journal of Medicine in 2009 made this statement about homeopathy:

It is considered unethical for modern medical practitioners to sink to this kind of deception that denies the patient his or her autonomy. Secondly, by opening the door to irrational medicine alongside evidence-based medicine, we are poisoning the minds of the public. Finally, if we don’t put a brake on the increasing self-confidence of the homeopathic establishment, they will cease to limit their attention to self-limiting or nonspecific maladies.

Baum and Ernst were correct in their evaluation, as you see in this roundup of homeopathic issues from around the world: Continue reading

Antivax 101: Tactics and Tropes of the Antivaccine Movement

Vaccines are NOT toxic
This is the first of a series of posts adapting a presentation made at The Ontario Public Health Convention in April, 2011. The presentation, “Fighting in the Trenches: Countering Anti-Vaccine Sentiment with Social Media” was a panel discussion from Scott Gavura and Kimberly Hébert:

One of the best parts of the infectious disease outbreak movie Contagion was the decision to include an antivaccinationist, conspiracy-minded, alternative health advocate, played by Jude Law. Law gave a character-perfect performance of someone intent on deliberately and selfishly thwarting public health advice, putting lives at risk as a consequence. Sadly, the writers didn’t have to look far for real world examples: It’s hard to forget “Health Ranger” Mike Adams’s paranoid music video produced in 2009, at the height of H1N1, when he decided to put every antivaccine argument into one performance.

But the Health Ranger is just the current manifestation of antivaccine sentiment which has been around since vaccines were invented:

When a theory has been confirmed so completely by facts as has the proposition that vaccination effectually performed will prevent an individual from contracting small-pox, or at least so fundamentally modify the disease that it is no longer a serious malady, there is in many minds a natural distaste to fight the battle again or to be constantly defending the position against the attacks of ill-informed or prejudiced persons.

- British Medical Journal, July 24, 1897

But this battle is still being fought, after over 100 years of immunization, and over two dozen diseases becoming vaccine-preventable. The anti-vaccine movement is a real movement, and it’s doing what it can to create fear, uncertainty and doubt regarding public health messaging. There is evidence that antivaccinationists can influence vaccination decisions. The arrival of social media over the past decade means there’s the need for public health advocates to adapt their messaging to this new medium. What seems clear is that “traditional” public health tactics, with warnings and arguments from authority, are dwindling in their effectiveness. All aspects of medicine are moving towards models of shared decision-making. This is an overdue change, and it’s been facilitated by the widespread availability of health information. Information is no longer hidden from public access. Want the approved product monograph for a vaccine? It’s available online. Even the primary literature is becoming more freely accessible.

Unfortunately, the power of the Web 2.0 and social media has made it easier for antivaccinationists to foster antivaccine fears and sentiment. In order to combat this misinformation, the movement’s tactics and tropes must be understood, so they can be called out.

Continue reading