Is it true that more than half of medical consultations are for MUS? A look at the evidence.

[Trish]

My aim on this thread is to share the results of my digging into this question over the last couple of days. I have found several papers with very different figures and will post them in a series of posts here.

The 52% claim:

The UK document, Guidance for commissioners of services for people with medically unexplained symptoms includes on page 6 the claim that:

Given the wide-ranging symptoms that can occur, patients have high rates of access to a number of outpatient departments. On average, 52% of patients accessing outpatient services have MUS, with the highest rates relating to gynaecology clinics (66%) and the lowest rate (37%) relating to dental services.

The primary source for this statement is given as this paper based on a study over 20 years ago by Wessely et al:

Nimnuan, T., Hotopf, M., and Wessely, S. Medically unexplained symptoms: an epidemiological study in seven specialties. J Psychosom Res 2001; 51: 361–367.

Abstract
OBJECTIVES:
This study aimed to estimate the prevalence and risk factors for medically unexplained symptoms across a variety of specialities.

METHODS:
A cross-sectional survey was conducted at two general hospitals in southeast London between 1995 and 1997. Eight hundred and ninety consecutive new patients from seven outpatient clinics were included. Demographic and clinical characteristic variables were assessed.

RESULTS:
Five hundred eighty-two (65%) of the subjects surveyed returned completed questionnaires. A final diagnosis was available in 550 (62%). Two hundred twenty-eight (52%) fulfilled criteria for medically unexplained symptoms. The highest prevalence was in the gynecology clinic (66%). After adjustment for confounders, medically unexplained symptoms were associated with being female, younger, and currently employed. Psychiatric morbidity per se was not associated with the presence of medically unexplained symptoms, but was more likely in those complaining of multiple symptoms. Those with medically unexplained symptoms were less disabled, but more likely to use alternative treatment in comparison with those whose symptoms were medically explained. Patients with medically unexplained symptoms were more likely to attribute their illness to physical causes as opposed to lifestyle factors.

CONCLUSIONS:
Medically unexplained symptoms are common across general/internal medicine and represent the most common diagnosis in some specialities. Medical behavior, training, and management need to take this into account.

Accessing the full paper on sci hub here

I have copied this from it:

Page 4

Prevalence and risk factors for medically unexplained symptoms

Approximately half (52%) of new attenders at the clinics above had at least one medically unexplained symptom.

Page 6

Comment

Medically unexplained symptoms were defined as current somatic complaints reported by patients for which conventional biomedical explanation could not be found on routine examination or investigations rated 3 months after the initial appointment….
...

Our result show that between one third and two thirds of patients attending general medical clinics do not receive a biomedical explanation of their distress.

Previous studies have suggested this in individual clinics, for example, only 16% of one clinics new outpatient attendees to a US internal medicine clinic was a definite biomedical cause identified for symptoms. [Kroenke et al]

[see later post - this seems to be wrong]

Van Hemert et al conducted a survey in a Dutch medical outpatient clinic showed that 52% of new referrals remained medically unexplained.’’

[I haven’t managed to access this paper yet]

My comments
The rest of the paper looked at demographic factors. They were surprised not to find an association between MUS and psych symptoms or disability level on their questionnaires.

Limitations of the study:
- The study was done in a tertiary care hospital, so is not representative of all patients.
- Only 62% of patients selected for the study responded and had sufficient data to be included. They did not investigate whether this was a skewed subset, perhaps patients with unexplained symptoms more eager to give feedback.

My conclusion:

52% of the 62% who provided data had at least one MUS symptom,

So of the initial 890 patients asked to take part:

32% reported at least one MUS symptom,

30% reported no unexplained symptoms,

38% didn’t respond and were not investigated for MUS.


I would conclude that somewhere between 32% and 52% had at least one symptom that remained undiagnosed. It is not clear from the paper whether the unexplained symptoms were the primary presenting symptom or a minor symptom that was not investigated or resolved naturally or whether any of the unexplained symptoms necessitated any repeat visits.


See next post for more studies.


My interest in this was stimulated by this post by @Diane O'Leary where she says:

Roughly speaking, 50% of outpatients' symptoms fall into that category (or at least this the figure you generally find in practice guidelines). The health system in the UK actually says 52%, so the majority of the time when people go to a doctor outside the hospital, the doctor concludes that the problem is MUS.

 

[Trish]

Following up this statement from the Wessely et al study in the previous post:

Our result show that between one third and two thirds of patients attending general medical clinics do not receive a biomedical explanation of their distress.

Previous studies have suggested this in individual clinics, for example, only 16% of one clinics new outpatient attendees to a US internal medicine clinic was a definite biomedical cause identified for symptoms. [Kroenke et al]

American Journal of Medicine

Common symptoms in ambulatory care: Incidence, evaluation, therapy, and outcome, Kroenke and Mangelsdorf 1989

Abstract

PURPOSE AND PATIENTS AND METHODS:
Many symptoms in outpatient practice are poorly understood. To determine the incidence, diagnostic findings, and outcome of 14 common symptoms, we reviewed the records of 1,000 patients followed by house staff in an internal medicine clinic over a three-year period. The following data were abstracted for each symptom: patient characteristics, symptom duration, evaluation, suspected etiology of the symptom, treatment prescribed, and outcome of the symptom. Cost estimates for diagnostic evaluation were calculated by means of the schedule of prevailing rates for Texas employed by the Civilian Health and Medical Program of the Uniformed Services for physician reimbursement.

RESULTS:
A total of 567 new complaints of chest pain, fatigue, dizziness, headache, edema, back pain, dyspnea, insomnia, abdominal pain, numbness, impotence, weight loss, cough, and constipation were noted, with 38 percent of the patients reporting at least one symptom. Although diagnostic testing was performed in more than two thirds of the cases, an organic etiology was demonstrated in only 16 percent. The cost of discovering an organic diagnosis was high, particularly for certain symptoms, such as headache ($7,778) and back pain ($7,263). Treatment was provided for only 55 percent of the symptoms and was often ineffective. Where outcome was documented, 164 (53 percent) of 307 symptoms improved. Three favorable prognostic factors were an organic etiology (p = 0.006), a symptom duration of less than four months (p = 0.009), and a history of two or fewer symptoms (p = 0.001).

CONCLUSION:
The classification, evaluation, and management of common symptoms need to be refined. Diagnostic strategies emphasizing organic causes may be inadequate.

My interpretation: Of 1000 patients, 38% reported at least one of their list of 14 symptoms that are commonly medically unexplained. ⅔ of these were tested and found organic explanations for 16%.

From the abstract, it is not clear whether these symptoms were the primary complaint the person was there for. For example, I might go to an internal med specialist for stomach pain, but also fill in on a form that I get headaches. That would not be investigated, as it’s not what I was there for. So it remains medically unexplained in that context.

From the abstract it seems that:

38% had symptoms on the list that might be MUS

If 16% of these were shown to be organic, this leaves about 32% with MUS

If 16% of the total were organic, that leaves about 22% with MUS

So it looks to me that Wessely et al have misquoted the figures, ending up with 84% with MUS instead of 22%.

I will see if I can get the full paper on Scihub and add to this post.
Edit: Full paper discussed in post #65.

 

[Trish]

Two papers about a single study. The first testing their Questionnaire to see if it’s suitable for diagnosing MUS, the second giving the results of their study of prevalence of MUS.

Korber, S., D. Frieser, N Steinbrecher and W. Hiller. 2011. Classification characteristics of the Patient Health Questionnaire-15 for screening somatoform disorders in a primary care setting. Journal of Psychosomatic Research 71(3): 142-147.

https://www.sciencedirect.com/science/article/pii/S0022399911000080?via=ihub

Abstract
Background
This study examines how effectively the Patient Health Questionnaire-15 (PHQ-15), a self-administered screening instrument, recognizes somatoform symptoms and somatoform disorders in a German primary care setting.

Methods
A selected sample of 308 patients (mean age 47.2 years, 71.4% women) from two regular primary care practices was screened with the PHQ-15 and additionally examined with structured interviews. Their primary care physicians rated symptoms reported in the interview as either “medically explained” or “medically unexplained.”

Results
Seventy-six percent of the symptoms were judged as medically unexplained. The PHQ-15 correlated significantly with the total number of symptoms as well as the number of somatoform symptoms (both r=0.63; P≤.001). A comparison between the most frequently reported symptoms in the interview and the 15 items of the PHQ-15 revealed that even though the PHQ-15 does not differentiate between medically explained and medically unexplained symptoms, it does catch many somatoform symptoms. When used to predict the diagnosis of a somatoform disorder, a cutoff of 10 points in the PHQ-15 was identified as optimal, resulting in a sensitivity of 80.2% and specificity of 58.5%. However, the cutoff has to be adjusted according to specific research or clinical purposes.

Conclusion
Several previous results could be confirmed, and under consideration of some limitations, the PHQ-15 seems to be a valuable tool for identifying somatoform symptoms and disorders in primary care.

So this was a study to test a questionnaire as a way of diagnosing somatoform disorder. 76% of the symptoms were classed as medically unexplained. And the conclusion is about what the cut off point should be on the questionnaire to diagnose somatoform disorder. The next paper is the same researchers and patients, and diagnoses about 23% of the patients as having somatoform disorder.

Steinbrecher, N. S. Korber, D. Frieser and W. Hiller. 2011. The prevalence of medically unexplained symptoms in primary care. Psychosomatics 52(3): 263-271.

https://www.sciencedirect.com/science/article/pii/S0033318211000533?via=ihub

Abstract
OBJECTIVE:
There is only a small number of studies dealing with the prevalence of medically unexplained symptoms and somatoform disorder in German primary care practices. Therefore, we aimed to study the prevalence of medically unexplained symptoms and the prevalences and comorbidities of somatoform and other mental disorders.

METHOD:
In the initial stage of a two-stage prevalence study, 620 consecutive patients were first screened with a PHQ-15 questionnaire. In the second stage, 308 selected persons were then interviewed in detail.

RESULTS:
Medically unexplained symptoms made up two-thirds of all reported symptoms with women, younger persons, and non-native speakers having the highest rates. The 12-months prevalences of somatoform disorders was 22.9%, for affective disorders it was 12.4%, and for anxiety disorders it was 11.4%. Somatoform disorder was comorbid with at least one other mental disorder in 43.2% of the cases. Most frequently, somatoform disorder was comorbid with anxiety or depression. 37.1% of the patients had a mental disorder.

CONCLUSION:
Somatoform and other mental disorders are highly common in primary care. In order to support an adequate management of mental and somatoform disorders, general practitioners should consider the influences of gender and cultural background on the development of a mental disorder.

If we assume somatoform disorders means the same as MUS the figure is 22.9%

Edit: Note - the 76% in the first paper refers to number of MUS symptoms, not number of patients, which was about 23%.

 

[Trish]

Swanson, L.M., J.C. Hamilton, and M.D. Feldman. 2010. Physician-based estimates of medically unexplained symptoms: A comparison of four case definitions. Family Practice 27(5): 487-493.

https://www.ncbi.nlm.nih.gov/pubmed/20634265

Abstract
BACKGROUND:
Medically unexplained symptoms (MUS) are considered a common occurrence in medical settings, although definitions, methodologies and resulting prevalence rates for MUS vary widely between studies.

OBJECTIVES:
The objective of the present study was to characterize physicians' estimates of MUS, including clinically significant MUS, and to demonstrate in a single study how estimates vary based on the definition used.

METHODS:
Two hundred and thirteen physicians completed an online questionnaire regarding the number of patients who present to their clinic with MUS. To reduce memory biases, participants reported on the number of patient seen in their most recent clinic day who met increasingly restrictive case definitions for MUS. Weekly estimates were also obtained.

RESULTS:
The least restrictive definition yielded an estimate of 11%. When certainty criteria were added to the definition of MUS, the estimate decreased considerably to 4%. Approximately 3% of patients were estimated to have chronic MUS that affected their daily functioning or caused significant distress (i.e. psychologically significant MUS), and only half of these, 1.5%, were assigned a diagnosis of somatoform disorder or factitious disorder. The proportion of MUS cases accounted for by malingering was 18%.

CONCLUSIONS:
The present study documents significantly lower estimates of MUS than chart review studies. However, our results suggest that a significant proportion of the total number of patients who present with MUS have abnormal illness behaviour associated with significant impairment or distress. Despite physicians' recognizing significant distress and dysfunction in these cases, formal diagnoses of somatoform or factitious disorder are rarely assigned.

My comment - between 3% and 11%

 

[Trish]

Medically Unexplained Physical Symptoms in Primary Care: A Controlled Study on the Effectiveness of Cognitive-Behavioral Treatment by the Family Physician

Article in Psychosomatics 50(5):515-24 · September 2009

https://www.researchgate.net/publication/38034480_Medically_Unexplained_Physical_Symptoms_in_Primary_Care_A_Controlled_Study_on_the_Effectiveness_of_Cognitive-Behavioral_Treatment_by_the_Family_Physician

Abstract

Disabling medically unexplained physical symptoms occur in 16% of all patients in primary care. The aim of this study was to assess the effectiveness of a cognitive-behavioral intervention by the family physician. In a controlled design with detailed information on patient selection, 6,409 patients were screened on somatoform disorder, and 65 participants were allocated to care-as-usual or the experimental condition. After 6 and 12 months, the cognitive-behavioral intervention by trained family physicians was not more effective than care-as-usual. Possibly, the intensity of treatment was insufficient for the severe and persistent symptoms that were encountered in primary care.

Somatoform Disorder in Primary Care: Course and the Need for Cognitive-Behavioral Treatment
Article in Psychosomatics 47(6):498-503 · November 2006

https://www.researchgate.net/publication/6680933_Somatoform_Disorder_in_Primary_Care_Course_and_the_Need_for_Cognitive-Behavioral_Treatment

Abstract

Medically unexplained physical symptoms are prevalent in primary care. Of all patients attending the family physician, 16% have a somatoform disorder as described by DSM-IV. Cognitive-behavioral treatment has been demonstrated to be effective in secondary care. However, the course of somatoform disorders and their need for treatment have not yet been established in primary care. In this study, data from 1,046 attendees in family practice were analyzed for prevalence, course, and eligibility for treatment. Over a 6-month follow-up, the prevalence of somatoform disorder decreased from 16.1% to 12.3%. After assessment of eligibility, about 5% of patients demonstrated a need for treatment.

Both papers by the same team quote a figure of 16% MUS or somatoform disorder in primary care.

 

[Trish]

That's as far as I've got so far.
In summary, we have figures ranging from 3% to 52% and mostly around 20%. This thread is open for discussion and any further papers and claims anyone can find.

 

[Peter T]

Thank you for sharing this important analysis. It certainly feels as if the data is being tortured to support an ideological position.

But even if the aprox 50% figure was accurate we do not have any idea what percentage of these people are suffering from [current] medical ignorance and what percentage if any have the presumed catch-all psychiatric diagnosis of psychosomatic Medically Unexplained Symptoms syndrome.

 

[Skycloud]

Thank you for your work on this @Trish.

 

[ME/CFS Skeptic]

Up to ... figures can be misleading. All you need is one bad study to increase the number.

Up to 70% of ME/CFS patients have POTS, but the real figure is probably somewhere around 25%. Up to 70% of ME/CFS patients have fibromyalgia, while the community study in Chicago gave a number of only 15%. The prevalence of ME/CFS goes way up to 6% because some flawed Chinese study estimated that number. The real prevalence, however, is somewhere around 0,2-0,4%. So while it seems to correct that one study estimated the percentage of patients accessing outpatient services having MUS at 50%, the real estimate seems much lower.

Keith Geraghty recently complimented Hartman and Rosmalen (both MUS-researcher who were on the Dutch health council) for citing lower prevalence estimates of MUS in primary care:

 

[Jonathan Edwards]

It seems to me this is much easier.

Ordinary headache is medically unexplained, despite various unconvincing explanations being popular (tension etc).

Everybody gets ordinary headaches.

So the prevalence of medically unexplained symptoms is 100%.
This is, if we are defining MUS simply as medically unexplained symptoms.

But clearly that is not what is meant by MUS for those who make a living out of it. They mean symptoms that are unexplained but are due to somatisation. This is clearly a contradiction because they are now explained.

So the prevalence of MUS is 0%.

You might think this was muddled thinking, or manipulation of words. Well, at least that seems to be the standard approach for MUS. If others can muddle and manipulate, why not me?

 

[Jonathan Edwards]

It really is quite worrying, however, that documents bandy about these figures, which are clearly intended to be 'facts' without any regard for accuracy.

The Wessely figure of 52% is not the number of patients accessing outpatients services. It is a (fudged) proportion of new patient attendances. If these people are accessing multiple clinics then they will, on average, be over-represented. Virtually all old patient attendances (which are about 80% in most clinics) will have specific diagnoses. But of course they are frequent attenders at a specific clinic. So that has to be factored in too.

What I think Wessely's data claims is that somewhere 32% of 20% of outpatient visits (6.4%) involve consultations by people who admit to unexplained symptoms when sent questionnaires from researchers interested in such symptoms. As a measure of how much of resources goes on such consultations this could be a meaningful number. If we really wanted to know what proportion of people accessing outpatient services fell into this category we would need other data.

But note that admitting to o ne unexplained symptom on a questionnaire is by no means an indication that the primary reason for attending clinic was for a symptom that remained unexplained. I reckon that I had a reasonable explanation for the main symptom for 95% of patients in my clinics. But as indicated I would expect 100% of these people to have had some headaches at some time.

So the Wessely study just makes no sense to me.
I will have a look at the others.

 

[Diane O'Leary]

Thank you, Trish, for looking into the question of where I got the 52% figure. You've found a lot of the central articles, and that's great. I wonder why you chose not to go the source, the paper I published on MUS in the #1 US bioethics journal? You'll find a great many references there, along with a discussion of the range of figures available in research (some of which you've noted here), and an assessment of what med ed and practice guidelines conclude given the astonishing range of estimates available in research.

That paper introduces MUS to the field of bioethics, so its opening is essentially a review paper - i.e. it serves the purpose of an expert literature review for those new to the area. When reviewers evaluate an article of this kind (and these are doctors, psychiatrists and bioethicists), they don't just go looking for a handful of easy access articles. Central figures are evaluated based on a reviewers' deep familiarity with all of the research in the area.

A journal of this ranking does not present controversial figures as factual. In a low ranking journal you might need to check, but in a top ranking journal you can trust that a core figure will be uncontroversial for the field. That is definitely not to say that the figure will be correct. It is only to say that it will represent typical professional understanding.

It's also helpful to note that this paper is a target article. That means it's published along with 12 other articles that consider and critique its contents. These are written by prominent experts in the field of MUS - mostly doctors and psychiatrists. This process in this journal is how bioethics considers new and important issues.

The best way to assess the validity of the 50% figure (that's the global figure I use, after noting that 52% is generally what they use in health policy in the UK), is to look and see how those 12 commentary and criticism papers respond to it. It's helpful to note that not one of those 12 critical evaluations of my article saw a need to debate the grounding figure of 50%. Again, that's not to say that it cannot be debated - but it is to say that according to the expertise of reviewers, and the 12 teams of professional experts who commented on the paper, it is correct to say that a figure of roughly 50% represents typical understanding.

Finally, to be very clear, the paper certainly does not accept that 50% of patients have MUS. It says this is a typical understanding, and then it goes on to consider in great detail what's actually happening with that portion of the patient population. All of what it says there supports your cause.

It's terrific that you guys are so astute about research, and able to explore the validity of what you read. It's very important, though, to see the difference between a non-professional looking for a handful of easy access papers and the process of peer review and commentary for the top ranked journal. That's not to say that peer review isn't faulty. Of course it is. But there's more to it than that. You need to know what kinds of things you can trust and what kinds of things you can't trust.

It is very common on s4me for objectivity to be obscured by loyalty to factions within the advocacy community. This is really not helpful to your understanding, to your cause, or to your spirits.

https://www.ncbi.nlm.nih.gov/pubmed/29697324
(There's a personal copy available at ResearchGate and on my website)

 

[Jonathan Edwards]

I am going to ignore the primary care paper because no GP can be expected to explain a whole load of symptoms that a specialist may be very familiar with and know the reason for. The idea that GPs know enough to diagnose somatoform disorder seems to me a symptom of the arrogance and laziness that has become pervasive in primary care.

 

[Jonathan Edwards]

The hospital clinic paper seems to me to provide a reasonably plausible figure of 3%. But it still looks as if it was done by people with a bias to finding more. They seem disappointed how few cases there were. Moreover, it seems that although these people had MUS not all had somatoform disorder because they distinguished this from malingering. And then the question is how do you know it is somatoform? And it is still highly likely that a significant proportion were unexplained because the physician was not skilled enough or experienced enough.

All in all though 3% looks to me to be a pretty reasonable figure.

 

[Jonathan Edwards]

Dear Diane (@Diane O'Leary). I really think you need to take on board that this group of people here on S4ME are way ahead in terms of intellectual debate than any stuffy old university department or journal whatever the impact factor. I debate here as an equal. I get caught out all the time. I am often dead wrong. Nobody cares what letters you have after your name or whether you are a professor. I find it hugely stimulating because I am constantly learning. Years ago I had a research group where we had this atmosphere but the academic environment as a whole is 95% phoney, whether medicine or philosophy.

Argument from authority ain't gonna wash here.

50% is not the 'typical understanding'. It is the bullshit that a small group of physicians and psychologists blather to each other to make each other feel important. If I suggested that 50% of patients coming to the UCH rheumatology clinic had MUS to my departmental journal club they would roar with laughter. It's fake news. Most physicians just get on with the job and ignore this sort of stuff.

 

[Arnie Pye]

The garbage about there being over 50% of patients with MUS and/or somatoform disorder must be compounded by the fact that there is no standard way of feeding back an accurate diagnosis to a doctor who found nothing wrong with the patient. Many cases of MUS must be solved eventually, not least because some cases of MUS must be life-threatening. But the doctors who found nothing wrong just continue on their merry way assuming that their rate of misdiagnosis or missed diagnosis is much better than it really is.

 

[Cheshire]

In a low ranking journal you might need to check, but in a top ranking journal you can trust that a core figure will be uncontroversial for the field.

Like the Lancet?

It's helpful to note that not one of those 12 critical evaluations of my article saw a need to debate the grounding figure of 50%.

If there is something I learned since becoming sick, it is that you always have to check by yourself.

It's terrific that you guys are so astute about research, and able to explore the validity of what you read. It's very important, though, to see the difference between a non-professional looking for a handful of easy access papers and the process of peer review and commentary for the top ranked journal.

By this standard, we should trust Wessely and ignore the Cochrane rebutal made by @Tom Kindlon and Robert Courtney.

 

[Trish]

I wonder why you chose not to go the source, the paper I published on MUS in the #1 US bioethics journal? You'll find a great many references there, along with a discussion of the range of figures available in research (some of which you've noted here), and an assessment of what med ed and practice guidelines conclude given the astonishing range of estimates available in research.

Thank you for pointing out your paper, @Diane O'Leary. I have had a look at it.

Why Bioethics Should Be Concerned With Medically Unexplained Symptoms

Diane O’Leary, PhD

The American Journal of Bioethics, 18:5, 6-15. https://www.tandfonline.com/doi/full/10.1080/15265161.2018.1445312
https://docs.wixstatic.com/ugd/23f4ba_d7559e609a6846a2b4523acf296362a7.pdf

Prevalence of MUS
Page 3

One well-known study (Kroenke and Mangelsdorf 1989) offers the astonishing finding that 86% of symptoms for which patients seek biological medical care remain medically unexplained in an internal medicine setting

.
See post #2 in this thread.

I have not been able to access the full Kroenke paper . I wonder where your figure of 86% comes from. It doesn't seem to fit with the abstract. Can you please explain where I've gone wrong.

 

[NelliePledge]

It is very common on s4me for objectivity to be obscured by loyalty to factions within the advocacy community. This is really not helpful to your understanding, to your cause, or to your spirits.

I thought we were all supposed to be allies?

Or is it actually ok to criticise allies after all.

 

[Diane O'Leary]

Dear Diane (@Diane O'Leary). I really think you need to take on board that this group of people here on S4ME are way ahead in terms of intellectual debate than any stuffy old university department or journal whatever the impact factor. I debate here as an equal. I get caught out all the time. I am often dead wrong. Nobody cares what letters you have after your name or whether you are a professor. I find it hugely stimulating because I am constantly learning. Years ago I had a research group where we had this atmosphere but the academic environment as a whole is 95% phoney, whether medicine or philosophy.

Argument from authority ain't gonna wash here.

50% is not the 'typical understanding'. It is the bullshit that a small group of physicians and psychologists blather to each other to make each other feel important. If I suggested that 50% of patients coming to the UCH rheumatology clinic had MUS to my departmental journal club they would roar with laughter. It's fake news. Most physicians just get on with the job and ignore this sort of stuff.

@Jonathan Edwards I have not made an argument from authority, as I have in no way suggested that you should believe my 50% figure based on my authority. In fact, there's not a word in there about my authority. To dispute what I've said in a credible way you'll need to take issue with the actual points I've made.

On that point it's helpful to note - as a matter of basic critical thinking - that there's a difference between a figure typically regarded as standard and a figure that doctors take seriously in practice. I have not said a word about the latter.