This post provides a tutorial for thyroid patients who want to analyze their own and each other’s health data without leading each other astray.
Our Thyroid Patients Canada peer-led private support group, recently launched in April 2020, is built on three basic principles (besides the obvious one of compassion and kindness):
- Share wisely
- Seek evidence
- Reason carefully.
Thinking critically about evidence is the core of the third principle: “Reason carefully.”
Thinking critically about how thyroid science and our health data can help us make reasonable therapeutic adjustments and experiments. It can also help us suggest to our doctors reasonable ways they can assist us.
If we want to hold our thyroid doctors, scientists, and health care systems accountable to the highest standards of evidence and scientific thinking, we ourselves should try to engage in critical thinking and careful interpretation of data in our patient peer support group.
If we resort to intellectual shortcuts and simple-minded thinking as we advise and assist each other, we may inflict on our own support community the very same vices we sometimes struggle with in the medical system.
If you are a thyroid patient (international members welcome) interested in this type of support group, please answer our 2 entry questions as you request to join.
Let’s sharpen our reasoning skills as we help each other.
Here are the topics I’ll cover:
- The three components of reasoning: Claim, Evidence, Analysis
- Cognitive Biases
- Fallacies of reasoning
- Paradigms in science
- Analyzing thyroid books and blogs
- Analyzing thyroid science
Meet your mentor
What I provide here is an advanced tutorial for moderators and peer support group participants.
I bring to this area my own expertise as a communications research professor and rhetorical scholar.
I teach these advanced critical thinking skills every day to my undergraduate and graduate students to equip them for professional and public life.
- My interest rhetoric focuses on producing ethical and reasonable argumentation. This skill goes hand in hand with the skill of detecting and defusing unethical and unreasonable arguments.
- My training in research focuses on the process of expanding our knowledge. This process involves avoiding problems with research design and data analysis.
Here, I’ll describe the basic reasoning processes that I try to use when I think about thyroid therapy and our thyroid health struggles.
I aim to use this process of reasoning when I analyze thyroid science and write my blog articles for Thyroid Patients Canada.
The 3 components of reasoning: Claim, Evidence, Analysis
A well-known theory is Stephen Toumin’s model of practical reasoning, which helps us understand how we reason in everyday life.
Here’s an example of a health argument. It reasons that Rick will probably get seriously sunburnt after sunbathing all day.
I use synonyms to boil down Toulmin’s system to 3 simpler components: Claim, Evidence, and Analysis.
I map these words onto the diagram above:
- A Claim (or conclusion)
- Evidence (or data or grounds) that may support the claim,
- Analysis of evidence, which involves the use of premises or assumptions, and critical thinking about other data and other possible claims.
Here’s an example of a thyroid-related health claim about the use of selenium dosing to help people with Hashimoto’s thyroiditis.
I’ve changed color to highlight the fact that now I’m giving an example of thyroid therapeutic reasoning.
1. A claim or conclusion.
A claim is a very focused opinion or “truth”-statement or a persuasive “should” statement. In thyroid peer support, it applies to a case, such as a specific patient’s concern or situation.
Often a claim comes first when we argue in everyday life.
People often want to know what our opinion is, and then they want us to explain what evidence and reasoning it’s based on.
A claim is like the destination sign on a bus. If we know a bus is going to Calgary, and we’re intrigued by that destination, we will be more willing to get on.
Claims tell us where the arguer intends to go. Once we get on a bus to Calgary, we’ll have confidence that barring any obstacles along the way, we’re likely to arrive at the destination.
Here’s an example of a claim in the form of some advice you might see on a thyroid support group:
“You could take 200 mcg of selenium per day to reduce your TPO antibody levels.”
Claims can either be informative, as in “The science seems to say that…” or persuasive and advisory, as in “X is a good solution, or Y is unwise,” or “Therefore, you should/could…”
Alternatively, if a person is not yet ready to make a claim, they may merely raise a topic or ask a question, or they may express a hypothesis in tentative language, as I’ve used “could” in the quotation above.
In the scientific research process, a reasonable hypothesis comes first, and a firm claim/conclusion comes only after collecting and analyzing the data.
However, even when scientists communicate their research in journals, they often begin by stating the conclusion they arrived at.
That’s why scientific articles have “abstracts.” They are a roadmap of the entire argument, and they provide the conclusion (claim) to the reader before the introduction begins.
2. Evidence or empirical data
“In 2017, Ventura and colleagues reviewed three scientific studies in which selenium at 200 mcg per day reduced TPO antibodies.”
“Upon diagnosis, I had TPO antibody levels over 1000. Five years later, I heard about the research on selenium and thyroid antibodies, and I talked to my doctor about it, and she decided to help me experiment with it by testing my antibodies and thyroid biochemistry. I took 200 mcg / day of Selenium, and over 1 year, my TPO antibodies reduced from 975 to 142. I did not change my daily dose of levothyroxine, but my FT4 levels rose by 5% and my FT3 by 9% of reference range”
Evidence should be of a type that is appropriate, and ideally sufficient, to support the type of claim.
These can be narratives, statistics, news, definitions, or informal or structured experiments, depending on what’s relevant to support a claim.
The more accurate and vivid the data, and the closer the source is to direct observation, and the more systematically the data is collected, the stronger the reasoning will be.
How much evidence is necessary to support a claim or health advice?
In a society and medical system biased toward numerical measurements and quantity more than quality, this is a difficult issue.
A large quantity of data or an authoritative source is certainly more helpful than one person’s experience because its weight can pile up.
However, a large pile of data is not always better. A study based on 1,000+ people could still be poorly designed, such as studies of TSH as a risk factor in osteoporosis but never considers how much T3 hormone is available in blood or whether the people have TSH receptor antibodies or problems with estrogen.
The data’s intrinsic quality and relevance to the nature of the claim is always important, regardless of its quantity.
In science, evidence can strongly support a hypothesis and may still not lead to absolute certainty. Oftentimes exceptions still exist that puzzle the scientists and clinicians.
Many of our thyroid health care system challenges are stonewalled by experts who say “There is insufficient evidence…” and they will conclude with a prohibition of therapeutic options or tests they do not favor.
There’s an ethical problem with this critique of “insufficient evidence.” Life is short, science is long, and human suffering can be intense.
Some people with a strong bias toward a paradigm will never be convinced, even if a mountain of evidence were piled up against their favorite opinion. When will evidence ever be “enough” if science is never perfect and consensus rules medicine?
“Insufficient evidence” and lack of 100% certainty is never a basis for absolute prohibition of a therapeutic choice or trial that could offer a patient a successful therapy.
It is our duty to seek for and closely look at the relevant evidence that does exist.
Often there is more evidence than we realize if we remove our biases against direct, primary observations from clinical data and a patient’s long personal experience with a disease. What about family history? Genetic data? Other relevant biochemistry?
A patient and doctor should have the right to conduct an “n=1” experiment (n = the number of people enrolled in a clinical trial) with voluntary consent from the patient. Both the patient and the doctor should be involved in evaluating the risks and benefits.
Ultimately, the patient’s body is his/her own, and the risk they bear is their own. The risk to the doctor’s career can be a professional obstacle in the way of therapy. If a therapeutic exception or experiment makes the doctor feel nervous about their own liability, the patient should be able to to sign a waiver.
According to Ventura et al 2017, selenium is involved in the process of protecting the thyroid gland from damage that often occurs in persons with high TPOAb antibody levels.
Ventura and colleagues engage in scientific reasoning when they try to explain the possible mechanisms by which selenium supply could influence autoimmunity and thyroid gland health.
- They reason that selenium is necessary to form glutathione peroxidase, a powerful antioxidant.
- Glutathione peroxidases in the thyroid protect thyroid tissue from fibrosis caused by the chemical reactions necessary to healthy thyroid function.
- Hashimoto’s thyroiditis is characterized by thyroid peroxidase antibodies (TPOAb).
- They considered a lot of secondary evidence, such as a study of selenium supplementation by Gartner, in which a reduction in TPOAb occurred along with signs of improved thyroid gland health, measured objectively.
However, we don’t know what blood levels of selenium need to be to have a beneficial effect.
Ventura and colleagues also reasoned carefully when they cautioned us:
“in most of the studies that focus on the relevance of selenium to thyroid disease, the authors did not measure selenium concentration prior to, during, and after supplementation.”
A person can analyze the data, showing how well the claim is based on reasonable assumptions or premises that a community can agree with.
Analysis usually relies on warrants, premises or presumptions, consisting of broader knowledge or theories about the way things work. We can’t critically reason about evidence without having some foundational beliefs, general knowledge, an ethical value system, and a context in which to interpret data.
Critical thinking during analysis considers the limitations of the data to support the claim, or other claims that could arise from the data, or other data that was not considered when arriving at this claim.
Bias and opinion: Not always bad.
The Cambridge Dictionary starts with the negative connotation of bias:
“the action of supporting or opposing a particular person or thing in an unfair way, because of allowing personal opinions to influence your judgment.”
A bias is like a leaning toward or against something. The problem is that it can be “unfair” and it can “influence your judgment” and cause reasoning to go off track.
Here’s how bias, opinion, and reasoning fit together like a chain:
- If you have an unfair bias that leads you to form an unexamined opinion, it can lead to fallacious or unethical reasoning.
“Supplements like selenium are generally more beneficial for health than treating hypothyroidism with thyroid hormones.“
Fallacious opinion based on unfair bias:
“One should try to avoid treatment with thyroid hormones and rely only on supplements like selenium.”
The very same dictionary that provides a negative definition for “Bias” provides a neutral, potentially positive meaning #2:
“the fact of preferring a particular subject or thing: For example,
‘She showed a scientific bias at an early age.'”
Here’s a neutral, or potentially positive, bias in thyroid support:
“One should consider the benefits of natural supplements like selenium in addition to treating hypothyroidism with thyroid hormones.“
Not all biases are bad, and opinions are necessary; our value systems and preferences build biases that make community and everyday life possible.
Having a good bias makes it easy to make decisions. Biases form habits and attitudes so that we can operate efficiently in urgent situations.
There is a time and place to ponder and reflect on the evidence-base for our bias. But in much of daily life, it would be very frustrating to stop and “overthink” things all the time.
In a support group, we also need to consider interpersonal factors. Is my opinion going to contribute to a social bias? Am I going to judge someone else as less worthy than me if they don’t share my bias and the opinions it leads to? Will I become arrogant or intolerant?
I hope not! Once I’m aware of my bias and the grounds of my opinion, I can be more tolerant and accepting that other people have different biases and opinions. All I have to do is remember the times in my own life when I didn’t hold this bias.
We’ll get farther if we understand that it’s not healthy to have too many unexamined biases and unquestioned opinions.
Your cognitive bias is…
One of the best free resources for sharpening our critical thinking is The School of Thought, a 501c3 non profit organization in the US, created by Jesse Richardson, Andy Smith, Som Meaden, and Flip Creative. They create free infographics on cognitive biases and fallacies.
The most common biases I see on thyroid support groups include:
“The first thing you judge influences your judgment of all that follows.”
For example, if we first experience LT4 monotherapy and it goes badly in a certain way, it influences our judgment of subsequent thyroid therapies we try.
Even if we were very underdosed because our TSH was sluggish, or another health issue interfered with LT4 therapy, we may have a strong bias against it and think that it will always be bad for us. And possibly other people too. Once burned, twice shy.
“You favor things that confirm your existing beliefs.”
If you believe that optimal thyroid hormone levels mean having a Free T4 at mid-range and a Free T3 in the upper third of reference, a pattern achievable for many patients taking desiccated thyroid hormone, you may seek only evidence in posts online and in support groups that confirm this belief about “optimal” thyroid levels.
You might even start to believe that this biochemical relationship is “optimal” for all people everywhere, no matter what thyroid therapy they are on, and even for people who aren’t on any thyroid therapy at all.
You are not going to seek out thyroid science articles by Ito et al, or Hoermann et al, that study LT4 monotherapy and show many people becoming symptom-free when their FT4 is at top of reference and their FT3 is somewhere around mid-reference, yet even they found that “optimal” was different for each and every single patient.
Confirmation bias goes hand in hand with “rationalization of disconfirmation,” the tendency to “explain away” evidence that contradicts your favorite beliefs.
Thus we often hear in thyroid support forums, “you’re still experiencing symptoms at optimal thyroid levels because of cortisol or iron.” If the patient explains that they have already tried optimizing their cortisol and their iron, the unfairly biased person will still believe that those thyroid levels are optimal for all patients, and something else is getting in the way.
Of course something else might be getting in the way, but let’s consider that maybe those optimal levels aren’t really optimal for the individual.
The halo effect
“How much you like someone, or how attractive they are, influences your other judgments of them.”
Celebrity status, physical attractiveness, and a charismatic delivery often trick us into believing people as authorities.
Dr. Westin Childs delivers attractive, authoritative videos, and he’s a charismatic personality. I might grow to really like him.
Therefore, what he teaches about thyroid health must all be equally true and authoritative. He wears a halo in my eyes, and my judgments of his claims are influenced by that halo.
I’m not saying the opposite is true, that Dr. Childs is wrong about everything, but that we should be aware of human cognitive biases. When we think about who our authorities are for thyroid knowledge, we should try to put aside this natural bias to put a halo on authorities / sources.
Everyone is fallible and imperfect, even the most revered thyroid scientists.
Think about what is being said, not just who said it and how elegantly they communicated.
The backfire effect
“When some aspect of your core beliefs is challenged, it can cause you to believe even more strongly.”
Some patients hold very strongly the myth that Reverse T3 blocks T3 from getting into cells. When this belief is challenged by pointing out that no known thyroid hormone transporters prefer to carry RT3 more than T3 and T4 into cells, the strong believer may say “I still believe it’s true because I felt hypothyroid when my Reverse T3 was above 15.” They have no way of supporting their belief scientifically, but they are resolved to believe it is a valid theoretical explanation for their experience.
They will cling strongly to this belief if they think it threatens the very foundation of many subsequent decisions they have made, such as their decision to adjust their thyroid therapy. Their erroneous theory will appear to be justified by the subsequent improvement they felt.
Sometimes the best way of approaching yourself or others is to ask questions that loosen one’s hold on a cherished beliefs, rather than directly attack those beliefs in a way that makes a person feel threatened.
It can take a long time to become aware of, and loosen our hold on, our cognitive biases. Be patient with yourself and others.
Avoiding and spotting fallacies of reasoning
Fallacies are common mistakes in reasoning that are weaknesses of human psychology found in every community.
For example, the “bandwagon fallacy” reasons that the individual should always follow the crowd: “Everyone I know improves with treatment X, so you should also improve with treatment X,” without further reasons as to why it works for the crowd and why it might not work for an individual.
Many lists of fallacies can be found online at https://yourlogicalfallacyis.com/
Common fallacies found in thyroid support groups include:
Appeal to nature
“Arguing that because something is ‘natural’ it is therefore valid, justified, inevitable, good or ideal.”
Thyroid fallacy example: Some people believe that desiccated thyroid extract (DTE), commonly known as “Natural desiccated thyroid” by patient groups, is more natural than, and therefore superior to, synthetic thyroid hormone pharmaceuticals because it is animal-derived. However,
- Synthetic thyroid hormone pharmaceuticals also contain molecules that are equally “bioidentical” — our bodies recognize the T4 hormone contained in Synthroid just as they recognize the levothyroxine provided by NDT medication.
- Also, how natural is it to live off the thyroid hormones of another animal? Any disease sets up a situation in which we need extraordinary aids or therapies to overcome natural disabilities.
- Thyroid disabilities are often caused by defects of nature, and the disabilities are not good. Therefore, nature is not always good.
Composition / Division
“Assuming that what’s true about one part of something has to be applied to all, or other, parts of it.”
Thyroid fallacy example: Many thyroid patients complain against ALL endocrinologists as rigid and unscientific doctors who are horrible at treating thyroid conditions, because MANY of them certainly are, as reported by thyroid patients. However,
- Not all endocrinologists are the same, and endocrinologists often have the professional freedom to treat patients’ thyroid condition as they believe is best.
- Independent-minded endocrinologists know that the guidelines include a “disclaimer” that permits them to use critical thinking and clinical evidence to treat thyroid disorders in ways that go beyond guidelines.
- Patients occasionally give very positive reports of endocrinologist-guided thyroid therapies, not just for thyroid cancers or hyperthyroidism, but also for hypothyroidism.
Doctors can fall into this fallacy too, believing that all the stories about whiny and unscientific thyroid patients are true and therefore, why should they listen to what you have to say about your therapy?
Even if 99% of people fit within our general characterization of a category, we must leave open our minds for the 1% who will surprise us and be nothing at all like the other people in their category.
Frameworks of reasoning: Paradigms
Shuttleworth & Wilson’s 2008 full article “What is a paradigm?” is worthy of a careful read by any thyroid patient or thyroid scientist.
Their article is licensed for re-use within a Creative Commons license, so here’s a lengthy passage, which ends at “[End of quotation]” below.
A scientific paradigm is a framework containing all the commonly accepted views about a subject, conventions about what direction research should take and how it should be performed.
The philosopher Thomas Kuhn suggested that a paradigm includes “the practices that define a scientific discipline at a certain point in time.”
Paradigms contain all the distinct, established patterns, theories, common methods and standards that allow us to recognize an experimental result as belonging to a field or not.
Science proceeds by accumulating support for hypotheses which in time become models and theories. But those models and theories themselves exist within a larger theoretical framework. The vocabulary and concepts in Newton’s three laws or the central dogma in biology are examples of scientific “open resources” that scientists have adopted and which now form part of the scientific paradigm.
Paradigms are historically and culturally bound. For example, a modern Chinese medical researcher with a background in eastern medicine, will operate within a different paradigm than a western doctor from the 1800s.
Where Does a Paradigm Come From?
Kuhn was interested in how the overarching theories we have of reality itself influence the models and theories we make about reality within that paradigm.
A paradigm dictates:
- what is observed and measured
- the questions we ask about those observations
- how the questions are formulated
- how the results are interpreted
- how research is carried out
- what equipment is appropriate
Many students who opt to study science do so with the belief that they are undertaking the most rational path to learning about objective reality.
But science, much like any other discipline, is subject to ideological idiosyncrasies, preconceptions and hidden assumptions.
In fact, Kuhn strongly suggested that research in a deeply entrenched paradigm invariably ends up reinforcing that paradigm, since anything that contradicts it is ignored or else pressed through the preset methods until it conforms to already established dogma.
The body of pre-existing evidence in a field conditions and shapes the collection and interpretation of all subsequent evidence.
The certainty that the current paradigm is reality itself is precisely what makes it so difficult to accept alternatives.
[End of quotation]
Thyroid health care policy, thyroid medical education, thyroid science, and even thyroid patient support groups can adopt paradigms.
Being aware of these powerful paradigms and how they affect our reasoning is as important as being aware of biases and fallacies that we so easily fall into.
Analyzing popular thyroid literature (books and blogs)
Now and then we should question even our favorite thyroid authors and thyroid bloggers, and question our own claims/opinions.
- Consider the strength of evidence that claims are based on and the logic that holds them together.
- Follow an author’s citations and reference list to see whether they truly support a claim. Sometimes people misinterpret the source.
- Do our own keyword searches in scientific databases to see whether other data also supports, or refutes, a claim.
- Inquire whether more recent information has been published.
Analyzing thyroid science itself
When reading scientific journal articles, an even deeper level of careful reasoning should be part of the process:
Question whether the claim/conclusion is dependent on narrow or flawed research methods of data collection, such as a study that
- didn’t measure T3 hormone concentrations (if relevant),
- didn’t examine any patients who had no thyroid glands (if relevant),
- didn’t rule out the effect of TSH-receptor stimulating or blocking antibodies (if relevant),
- didn’t study how desiccated thyroid therapy worked differently than LT4 monotherapy (if relevant).
Question how the data was organized and why. Part of methodology has to do with categorizing and structuring a data set, and performing one analytical procedure before performing another. Ask yourself,
- Why was the data analyzed through one lens first, and another lens next? How did that affect the analytical thinking and statistical results?
For example, many studies look at all the data first through TSH and the boundaries of its reference range. This is because TSH is presumed to be the sensitive indicator of all things thyroid.
However, TSH is an indirect measure of thyroid hormones and does not always regulate or respond to them well.
How would the results of their analysis differ if they organized patients by tertiles (3 groups) or quintiles (5 groups) ranging from higher T4 or T3 and lower T4 or T3 levels above, within, and below reference range, and only secondarily considered where their TSH fell?
CAUTION: A lot of thyroid science is limited due to methodological choices and blind spots, but that does not make it useless.
A single study can’t do everything, nor even a set of 10 studies.
But consider how many incorrect conclusions and assumptions are being made by extending findings from a narrow set of research methods to very different populations and situations!
Discern the degree to which the reasoning employs unexamined or unproven premises (biases, opinions) as a filter or lens to structure and analyze the data.
There is nothing preventing cause-effect relationships from being two-way (reciprocally reinforcing) and from being more complicated than one can perceive.
For example, why is a “nonthyroidal illness” such as ischemic heart disease always considered a cause of low T3 and high Reverse T3, but never consider that this disordered biochemistry can also be caused by thyroid disease and inappropriate therapeutic responses to it?
What if, in some thyroid patients, years of therapy-induced low T3 causes or at least contributes to the development of ischemic heart disease?
The interpretation of data can go very wrong if a theory or a paradigm is blind to any other alternatives, yet conveniently upholds existing beliefs and practices within medical education, policies, guidelines, pharmaceuticals, and laboratory tests.
Research can often act as a way of reinforcing and validating a cherished and convenient paradigm, more than the truth about thyroid health.
For example, a lot of research on hypothyroid therapy takes as a paradigmatic assumption that the ratio of T4 and T3 thyroid hormone dosing should strictly imitate the average ratio of thyroid gland secretion found in the thyroid-healthy population of 14 people studied by Pilo et al in 1990 , which was found to be approximately 1:14.
This idea takes the verbal analogy of “thyroid hormone replacement” literally without questioning the degree to which a pill can “replace” a living gland.
However, scientists offer a special exception to LT4 monotherapy, which is permitted to be an unphysiological and imbalanced ratio of 0 : 100 because it has been a consensus-based therapeutic bias since the 1990s. Therefore, they are strongly biased toward giving excess T4 hormone, but against giving what they consider “excess” T3 hormone.
This bias toward one 1990 article’s statistical average, and toward the consensus-based pharmaceutical choices of a medical field, has resulted in the mistaken bias that I identify as “thyroid pharma prejudice,” the belief that one thyroid hormone preparation is intrinsically superior to another, or that some are intrinsically more dangerous because of their T3:T4 ratio or their animal or synthetic source.
Another example: It is commonly believed that therapy should target statistical reference ranges found in the thyroid-healthy population.
However, the thyroid-disabled often have unique physical and/or genetic disabilities that intrinsically imbalance their thyroid biochemistry. In addition, thyroid hormone therapies directly bias and distort biochemistry.
This paradigm that correction of a thyroid disability must target the statistical biochemical features of thyroid health has resulted in a bias I call “biochemical bigotry,” a phenomenon that arose as thyroid biochemical tests and the TSH test were being refined in the 1980s and 1990s.
CAUTION: Question the paradigms and methods of science, but as you do, be open-minded to seeing all the truths and data mixed in with the mistaken reasoning.
Do not assume that common paradigms and practices are baseless. They do have some basis in evidence and physiology, or they would not be so convincing!
That’s my tutorial. Let’s keep learning as we try our best to practice these forms of reasoning.