Tag: anecdotes

Hierarchy of Evidence and Vaccine Papers

Evidence is evidence, right?

Nope.

There is a hierarchy of evidence, from weakest to strongest, that help folks make decisions about science and medicine.

That’s why you can’t just search Google or PubMed, read abstracts, and say that you have done your research.

Hierarchy of Evidence

For any study, you have to review and judge the quality of the evidence it provides.

A meta-analysis with over 1.2 million kids found that vaccines were not associated with autism, while Wakefield's retracted case series included only 12 children.
A meta-analysis with over 1.2 million kids found that vaccines were not associated with autism, while Wakefield’s retracted case series included only 12 children.

Is it a case report (a glorified anecdote), case series, or animal study (lowest quality evidence)?

Or a systemic review or meta-analyses (highest quality evidence)?

“The first and earliest principle of evidence-based medicine indicated that a hierarchy of evidence exists. Not all evidence is the same. This principle became well known in the early 1990s as practising physicians learnt basic clinical epidemiology skills and started to appraise and apply evidence to their practice. Since evidence was described as a hierarchy, a compelling rationale for a pyramid was made.”

Murad et al. on the New Evidence Pyramid

What about case control studies, cohort studies, and randomized controlled trials?

They lie somewhere in between on the hierarchy of evidence scale or pyramid.

And there are other factors to consider when judging the reliability of a study.

“Ultimately, the interpretation of the medical literature requires not only the understanding of the strengths and limitations of different study designs but also an appreciation for the circumstances in which the traditional hierarchy does not apply and integration of complementary information derived from various study designs is needed.”

Ho et al. on Evaluating the Evidence

For example, you might also have to take into account the sample size of the study.

A study can be underpowered if it doesn’t have enough subjects. Unfortunately, even an underpowered study will give you results. They likely won’t be statistically significant results, but folks don’t always realize that.

Even a meta-analysis, usually considered to be at the top of the hierarchy of evidence pyramid, can have problems that make their results less useful, such as not using appropriate inclusion criteria when selecting studies and leaving out important studies.

All in all, there are many factors to look at when reading a medical paper and considering if the results are valid and should influence what you do and how you think. This is especially true when looking at low quality vaccine papers, many of which the anti-vaccine movement uses to scare people, even though they are often poorly designed, and several of which have been retracted.

What to Know About the Hierarchy of Evidence

Learning about the hierarchy of evidence can help you better evaluate medical studies and vaccine papers and understand that there is more to doing your research about vaccines than searching PubMed and reading abstracts.

More on the Hierarchy of Evidence

 

Recommendations for Reporting About Vaccines

Historically, the media has played a huge role in pushing vaccine misinformation and scaring parents away from vaccinating and protecting their kids.

“The media created the MMR hoax, and they maintained it diligently for 10 years.”

Dr. Ben Goldacre Bad Science

Even before Andy Wakefield and his MMR hoax, the media helped fuel pertussis outbreaks by pushing the flawed research of John Wilson, which led to lawsuits against DPT vaccines and a big drop in vaccination rates.

None of it was true and the lawsuits failed, but the consequence was still that many unvaccinated kids died.

Bob Sears appeared on Fox & Friends in 2010 for the segment "Vaccines: A Bad Combination?"
Bob Sears appearing on Fox & Friends in 2010 for the segment “Vaccines: A Bad Combination?” is a great example of false balance.

Many others in the media have done a great job in promoting myths and fake controversies about vaccines and have used false balance in their interviews and articles to scare parents.

Fortunately, things have gotten better over the years.

Important Points for Reporting About Vaccines

Still, despite what some folks might think, health journalists aren’t going to get in trouble for reporting about vaccines.

They are going to hear about it if they do a bad job though.

“…it is important to recognise that the balance of media reporting does not necessarily reflect the balance of the argument among the involved professionals – by this is meant that equal weighting might be given by the media (and thus the lay community) to those for and against the vaccine although opponents of vaccination might be a very small number, as for example happened with both pertussis and MMR.”

David Baxter on Opposition to Vaccination and Immunisation the UK Experience – from Smallpox to MMR

Remember, the way that health journalists cover vaccines and vaccine-preventable diseases can influence the behavior of people, either helping them understand that vaccines are safe and necessary, putting them on-the-fence about vaccines, or scarring them away from getting vaccinated and protected.

So be careful when reporting about vaccines, as it gives you the opportunity to correct many of myths that scare people, while educating folks about the topic you are covering.

You should also:

Are you ready to cover your next story about vaccines or the next measles outbreak?

What to Know About Reporting on Vaccines

The way that health journalists cover vaccines and vaccine-preventable disease outbreaks can influence the behavior of people, either helping them understand that vaccines are safe and necessary, putting them on-the-fence about vaccines, or scarring them away from getting vaccinated and protected.

More on Reporting about Vaccines

Who Is Dr. Taz?

Dr. Taz is on a mission “to transform the way we do medicine and empower and equip you with the best tools so you can live your healthiest life.”

While that sounds very nice, it doesn’t take too long to figure out that she seems like every other anti-vaccine quack we run across these days.

Who Is Dr. Taz?

Dr. Tasneem Bhatia MD (Dr. Taz) describes herself as a nationally recognized “wellness expert” who became a “pioneer and trailblazer” after overcoming her own personal health problems.

With multiple office locations and membership packages, Dr. Taz is pleased to offer many non-evidenced based services for you and your child, and she will even file your claim forms from your insurance company, although, as expected, she doesn’t actually participate in any insurance plans.

What about vaccines?

“My journey in medicine began with pediatrics, so I am well aware of the importance of vaccines and the incredible history and success of vaccination programs in reducing infant and child mortality.

Yet as my journey continues, I have had to listen to patient after patient describe a change or a shifting in their children once vaccines were administered. I experienced this as a parent. I will never forget the day that my son received a combination vaccine. Within 24 hrs., his mild reflux became severe, his weight gain over the next few months slowed and we continue to play catch up, trying to analyze our next steps. My son, however, is not autistic. He is brilliant, hilarious, and an absolute charmer.

My patients and my own children have forced me to rethink this vaccine controversy.”

Dr. Taz on Back to School Survival Series Part Two, The Vaccine Debate Continues

Of course, there is no vaccine controversy, except the one that folks like Dr. Taz have created. Like many other vaccine-friendly pediatricians, anecdotes became evidence and quickly overcame years of learning.

And shame on Dr. Taz for implying that autistic kids are not brilliant, hilarious and charmers!

That’s the vaccine controversy. Continuing to push the idea that autistic kids are vaccine damaged and not understanding the simple concept that correlation doesn’t imply causation.

“Red flags for parents that may justify an alternative schedule include”

Dr. Taz on Back to School Survival Series Part Two, The Vaccine Debate Continues

While there are true contraindications to getting vaccinated, she doesn’t list any of them, instead pushing anti-vaccine talking points about skipping or delaying vaccines if your child has reflux, colic, or delayed milestones, etc.

But there’s more.

During a visit with Dr. Taz, you can also get your child:

  • a Zyto scan
  • Meridian testing
  • a brain boost evaluation
  • sports optimization testing

And parents can get a detox screen “which will directly correlate with your child’s early ability to detox and process chemicals.”  That’s probably just MTHFR testing, which you don’t need and which doesn’t correlate with much of anything, besides homocystinuria.

Selling supplements is big business for integrative, holistic, and anti-vaccine folks.
Your diagnostic tests and evaluation, whether it is the Zyto scan or detox screen, likely helps them scare convince you into buying more supplements.

Dr. Taz also offers:

  • acupuncture and Chinese medicine
  • aromatherapy
  • Ayurveda (Indian medicine)
  • energy healing
  • essential oils
  • craniosacral therapy (osteopathy)
  • homeopathy
  • IV therapy

Now, I understand that these types of holistic docs push the idea of “pulling from conventional, integrative, holistic, functional and Chinese medicine to create the best customized treatment plans possible,” but if any of these alternative therapies worked, whether it was acupuncture or Ayurveda, or homeopathy, then why do they need to integrate them all?

So what services does Dr. Bhatia offer to bring her patients to “whole health”? It’s a veritable cornucopia of quackery. Homeopathy? Check. Acupuncture? Check. (Obviously.) IV vitamin therapy? Check. Oh, and of course Dr. Bhatia offers thermograms. She even offers mobile thermograms. Never mind that thermography remains an unvalidated test for the early detection of breast cancer, much less for all the other conditions for which Dr. Bhatia recommends it, such as arthritis, fibromyalgia, back injuries, digestive disorders, “and more…”

A commercial for acupuncture masquerading as news

And how does someone go from teaching medical students and residents at Emory University to being one of Gwyneth Paltrow’s Goop experts, along with Kelly Brogan?

Dr. Taz was a pediatrician who said that vaccines were safe and necessary.
It wasn’t so long ago that Dr. Taz was a pediatrician who said that vaccines were safe and necessary.

Or from saying vaccines are safe and necessary and that parents shouldn’t expose their kids at chicken pox parties to a few years later saying that we shouldn’t judge Kristin Cavallari because we need more vaccine research.

What motivates these folks?

What to Know About Dr. Taz Bhatia

Dr. Taz promotes herself as an integrative medicine expert who pushes many unproven treatments and has alternative and dangerous views about vaccines and autistic kids.

More on Dr. Taz Bhatia

Can Vaccines Cause Multiple Sclerosis?

Multiple Sclerosis is thought to be an autoimmune disease, with symptoms typically starting when you are between 20 to 40 years old.

“MS symptoms are variable and unpredictable. No two people have exactly the same symptoms, and each person’s symptoms can change or fluctuate over time. One person might experience only one or two of the possible symptoms while another person experiences many more.”

National Multiple Sclerosis Society on MS Symptoms

From fatigue, weakness, and problems walking to vision problems, including the onset of blurred vision, MS can have many different symptoms.

What Causes Multiple Sclerosis?

Some people may be surprised that doctors have known about Multiple Sclerosis since the 1870s. They recognized people with the symptoms of MS even earlier.

Unfortunately, we still don’t know what causes it.

Can Vaccines Cause Multiple Sclerosis?

Without a known cause, it is easy to understand why some folks blame vaccines.

How many infants got hepatitis B in France because of low levels of vaccination after they blamed the vaccine for causing MS?
How many infants got hepatitis B in France because of low levels of vaccination after they blamed the vaccine for causing MS?

We see the same thing with many other conditions.

Remember though, just because you don’t know what causes something doesn’t mean that you can’t eliminate things that don’t cause it.

“Concern about hepatitis B vaccination arose from France in the mid 1990s. Following a mass hepatitis B vaccination program in France there were reports of MS developing in some patients a few weeks after receiving the vaccine. In 1998, the French government stopped the school-based hepatitis B component of the vaccination program while they investigated a possible relationship between hepatitis B vaccine and demyelinating disease. When studies of the French vaccine recipients were completed they showed that there was not a significant increase in the number of vaccinated people who developed MS as compared with those who had never received hepatitis B vaccine.”

Hepatitis B and multiple sclerosis FactSheet

And more than a few studies have shown that vaccines do not cause Multiple Sclerosis.

From the hepatitis B vaccine to the HPV vaccines, it has been shown that vaccines do not cause Multiple Sclerosis.

It has also been shown that vaccines don’t increase the risk of relapses for people who already have MS.

“…vaccines are able to prevent some infections in MS patients known to accelerate the progression of the disease and increase the risk of relapses.”

Mailand et al on Vaccines and multiple sclerosis: a systemic review

And yes, since new infections may trigger MS relapses, vaccines have an added benefit for MS patients.

And that’s why it is recommended that patients with MS follow the standard Centers for Disease Control immunization schedule. They may need to avoid getting live vaccines while taking specific MS medications though, as some of these can suppress their immune system.

“In the last few years a number of MS-focused vaccines have shown promising results in early phase clinical trials, and with each success the technology is closer than ever to offering a viable treatment option.”

Dr. Karen Lee on MS vaccines: Thinking outside the box for new treatments

While everyone hopefully now understands that any talk about MS being associated with vaccines is just another myth or scare tactic of the anti-vaccine movement, vaccines may one day really be associated with MS – therapeutic vaccines are in development that can treat people with Multiple Sclerosis!

What to Know About Vaccines and Multiple Sclerosis

Although it is still not known what does cause Multiple Sclerosis, we do know that it is not vaccines, which may actually reduce the risk of relapses for folks who already have MS.

More on Vaccines and Multiple Sclerosis

Can Vaccines Cause POTS?

Have you ever heard of POTS?

“In POTS, the lightheadedness or fainting is also accompanied by a rapid increase in heartbeat of more than 30 beats per minute, or a heart rate that exceeds 120 beats per minute, within 10 minutes of rising.”

NIH Postural Tachycardia Syndrome Information Page

POTS or postural orthostatic tachycardia syndrome was first identified in the early 1990s and can cause many debilitating symptoms, such as dizziness, headaches, and fatigue.

What Causes POTS?

We don’t know what causes POTS.

“The term “POTS” was coined in 1993 by a team of researchers from Mayo Clinic, led by neurologist Dr. Philip Low. However, POTS is not a new illness; it has been known by other names throughout history, such as DaCosta’s Syndrome, Soldier’s Heart, Mitral Valve Prolapse Syndrome, Neurocirculatory Asthenia, Chronic Orthostatic Intolerance, Orthostatic Tachycardia and Postural Tachycardia Syndrome.”

Dysautonomia International on POTS

Well, we know that POTS is caused by a malfunction of the patient’s autonomic nervous system (dysautonomia), but we don’t know always know what causes or triggers that malfunction.

Sometimes we do though, as POTS has been associated with other types of dysautonomia, like Ehlers-Danlos Syndrome and Mast Cell Disorders.

And genetics may play a role in some people with POTS.

Can Vaccines Cause POTS?

It shouldn’t be surprising that some folks think that vaccines could be associated with POTS.

“Anyone at any age can develop POTS, but the majority of individuals affected (between 75 and 80 percent) are women between the ages of 15 to 50 years of age.”

NIH Postural Tachycardia Syndrome Information Page

That’s right.

As more people were becoming aware of POTS, some of them were getting vaccinated for HPV.

But that correlation certainly doesn’t mean that vaccines cause POTS.

“POTS is a condition that causes lightheadedness or fainting and a rapid increase in heartbeat upon standing. The cause is unknown, but doctors think POTS may be associated with a number of risk factors and syndromes, including: a recent viral illness, physical deconditioning, chronic fatigue syndrome and nervous system problems.”

CDC on Can HPV vaccines cause POTS?

And studies have confirmed that, including:

  • In 2015, the European Medical Association confirmed evidence that HPV vaccines do not cause complex regional pain syndrome (CRPS) and postural orthostatic tachycardia syndrome (POTS)
  • A review of VAERS reports that “did not detect any unusual or unexpected reporting patterns that would suggest a safety problem” with HPV vaccination, including extra cases of POTS
  • A study in the UK using the MHRA’s Yellow Card passive surveillance scheme found no increase in reports of chronic fatigue syndromes following the introduction of Cervarix
  • A large, nationwide register-based study from Norway found no indication of increased risk of chronic fatigue syndrome/myalgic encephalomyelitis following HPV vaccination
  • A large cohort study of over 2 million young girls in France found no risk for autoimmune diseases (including neurological, rheumatological, hematological, endocrine, and gastro-intestinal disorders)
  • A large cohort study of girls in Sweden with pre-existing autoimmune diseases found that HPV vaccination was not associated with increased incidence of new-onset autoimmune disease (49 types of autoimmune diseases)

Contrast those large studies that are evidence against any association between vaccines and POTS with the case reports, anecdotal evidence, and vaccine scare stories that say there is.

“There is currently no conclusive evidence to support a causal relationship between the HPV vaccine and POTS. It is of utmost importance to recognize that although temporal associations may be observed, conclusions of causality cannot be drawn from case reports and case series due to the small sample size and lack of control population inherent to this type of scientific literature. If POTS does develop after receiving the HPV vaccine, it would appear to do so in a small subset of individuals and would be difficult to distinguish from the normal prevalence and incidence of the disorder.”

Butts et al on Human Papillomavirus Vaccine and Postural Orthostatic Tachycardia Syndrome: A Review of Current Literature

What about other vaccines? Could they cause POTS?

Folks should remember that a case report is basically a gloried anecdote and is not the kind of evidence you should use to make decisions about vaccinating and protecting your kids.
Folks should remember that a case report is basically a gloried anecdote and is not the kind of evidence you should use to make decisions about vaccinating and protecting your kids.

While the focus has been on the HPV vaccines, an issue with other vaccines causing POTS would have been picked up with our current vaccine safety systems.

But why has the focus been on the HPV vaccines?

It is an easy association to notice, after all POTS begins to occur right around when the HPV vaccines are given (teen years) and the HPV vaccines are given in many different countries. Most other vaccines that we give to teens in the United States, including Tdap and the meningococcal vaccines, aren’t as widely used in other countries.

But remember, POTS isn’t a new diagnosis. That anti-vaccine groups are latching onto it to scare parents away from vaccinating and protecting their kids is.

What to Know About Vaccines and POTS

There is no evidence that vaccines, especially the HPV vaccines, cause POTS.

More on Vaccines and POTS

Can Vaccines Cause Transverse Myelitis?

Transverse myelitis is not common, so most people probably haven’t heard of it.

“The term myelitis refers to inflammation of the spinal cord; transverse refers to the pattern of changes in sensation—there is often a band-like sensation across the trunk of the body, with sensory changes below.”

Transverse Myelitis Fact Sheet

The symptoms of transverse myelitis depend on where the inflammation occurs and sometimes, on the cause. They can include back pain, weakness or paralysis of the legs and arms, paresthesias (sensory alterations in the neck, arms, or legs), and bowel and bladder dysfunction.

What Causes Transverse Myelitis?

An MRI of a teen with transverse myelitis.
An MRI of a teen with transverse myelitis that resolved after total body irradiation therapy was stopped.

Many things can cause transverse myelitis.

Possible triggers can include:

  • infections – following bacterial, viral, fungal, and parasitic infections
  • immune system disorders
  • inflammatory disorders
  • vascular disorders

Unfortunately, it isn’t usually known what causes someone to develop transverse myelitis.

There are treatments though and many people with transverse myelitis have at least a partial recovery, although it may take months to years.

Transverse myelitis is not thought to be genetic and rates are highest in two age groups – those between 10 and 19 years (when many preteens and teens get vaccinated) and those between 30 and 39 years.

Can Vaccines Cause Transverse Myelitis?

Have you heard that vaccines can cause transverse myelitis?

“Vaccines currently routinely recommended to the general population in the U.S. have not been shown to cause transverse myelitis.”

Institute for Vaccine Safety on Do Vaccines Cause Transverse Myelitis?

While there are some case reports that tell of a temporal association between getting a vaccine and later developing transverse myelitis, the evidence does not support any association.

Why do we see these case reports?

Just like SIDS, autism, type 1 diabetes, and many other conditions, transverse myelitis has a background rate of disease or a number of cases that you can expect to occur in a given population. Once you know this background rate, you can then predict how many people will coincidentally develop transverse myelitis within one, seven, forty-two, or more days after they are vaccinated.

With a background rate of about 0.36 per 100,000 people, if one million get a vaccine, you would expect:

  • at least 1 to 2 of them to develop transverse myelitis coincidentally after 1 day
  • at least 1 to 2 of them to develop transverse myelitis coincidentally after 7 days
  • at least 2 to 4 of them to develop transverse myelitis coincidentally after 42 days

If the rate is higher than that, it could indicate a problem.

Let’s do the math.

There are about 1,400 new cases of transverse myelitis in the United States each year.

How many vaccines are given? About 286 million doses – each year. Some of those are given on the same day, but that would still mean that 100s of people should be getting transverse myelitis within 1 to 7 days if vaccines were a cause.

They aren’t.

“Correlation does not imply causation.”

In fact, an Institute of Medicine report, Adverse Effects of Vaccines: Evidence and Causality, dismissed most of the evidence for an associated between vaccines and transverse myelitis as insufficient and lacking.

And further studies found no association:

  • A Vaccine Safety Datalink study, Acute Demyelinating Events Following Vaccines: A Case-Centered Analysis, looked at nearly 64 million vaccine doses of vaccines and also “found no association between TM and prior immunization.”
  • Another study, Maternal safety of trivalent inactivated influenza vaccine in pregnant women, used “a large, geographically diverse, retrospective cohort of pregnant women” and found no cases of transverse myelitis.

Not only do vaccines not cause transverse myelitis, but many vaccine-preventable diseases can. So vaccines can likely protect you from developing transverse myelitis by protecting you from these diseases!

What to Know About Transverse Myelitis

Vaccines do not cause transverse myelitis, although many vaccine-preventable diseases can.

More on Transverse Myelitis

Anecdotes as Evidence

Evidence is evidence, right?

Not really.

There is a hierarchy of evidence, from weakest to strongest, that help folks make decisions about science and medicine.

In an age when everything is evidence of something, remember that anecdotes are not scientific evidence.

That’s why you can’t just search PubMed, read abstracts, and say that you have done your research. For any study, you have to review and judge the quality of the evidence it provides.

Is it a case report (a glorified anecdote), case series, or animal study (lowest quality evidence) or a systemic review or meta analyses (highest quality evidence)?

What about case control studies, cohort studies, and randomized controlled trials? They lie somewhere in between on the hierarchy of evidence scale.

Anecdotes as Evidence

And where do anecdotes fit in?

“Anecdotes are uncontrolled subjective observations. I have often criticized reliance on anecdotes, which is especially problematic in medicine. The problem with anecdotes is that they are subject to a host of biases, such as confirmation bias. They are easily cherry picked, even unintentionally, and therefore can be used to support just about any position. For every anecdote, there is an equal and opposite anecdote.”

Steven Novella on The Context of Anecdotes and Anomalies

Anecdotes are not scientific evidence.

Unfortunately, some people use anecdotal evidence to make some very serious decisions, including skipping or delaying their children’s vaccines, leaving them unvaccinated and unprotected.

“An anecdote is a story – in the context of medicine it often relates to an individual’s experience with their disease or symptoms and their efforts to treat it. People generally find anecdotes highly compelling, while scientists are deeply suspicious of anecdotes. We are fond of saying that the plural of anecdote is anecdotes, not data.”

Steven Novella on The Role of Anecdotes in Science-Based Medicine

Believing that anecdotes are important scientific evidence is also what often drives some pediatricians to pander to fears that parents may have about vaccines, helping them create non-standard, parent-selected, delayed protection vaccine schedules.

What else do you need to know about anecdotal evidence?

Anecdotes are basically the fuel of the anti-vaccine movement.

“With little or no evidence-based information to back up claims of vaccine danger, anti-vaccine activists have relied on the power of storytelling to infect an entire generation of parents with fear of and doubt about vaccines. These parent accounts of perceived vaccine injury, coupled with Andrew Wakefield’s fraudulent research study linking the MMR vaccine to autism, created a substantial amount of vaccine hesitancy in new parents, which manifests in both vaccine refusal and the adoption of delayed vaccine schedules.”

Shelby et al on Story and science

Well, anecdotes and fear – often combined in vaccine scare videos.

If you have been making your vaccine decisions based on anecdotes, it is time to do a little more research and get better educated about vaccines.

What to Know About Anecdotes as Evidence

Anecdotes, although they are easy to believe, are not scientific evidence, and certainly shouldn’t persuade you that vaccines aren’t safe, that vaccines aren’t necessary, or that vaccines are associated with autism.

More on Anecdotes as Evidence