Fall 2021 (Volume 31, Number 3)
Managing Uncertainty
By Philip A. Baer, MDCM, FRCPC, FACR
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“We crave explanations for most everything, but innovation and progress happen when we allow ourselves to
embrace uncertainty.”
– Simon Sinek, author and inspirational speaker
Two referrals came in this week on patients I had seen
before. Patient #1 had been seen four years ago with
an isolated stably high CK1 in the hundreds, not on
statin therapy, not hypothyroid, with no rash, weakness or
muscle atrophy. I provided reassurance and sent them back
to their primary care provider. Patient #2 had been seen
10 years ago, with a positive ANA2 test 1/640 speckled/
homogeneous, a relative with rheumatoid arthritis (RA),
and mild fatigue and arthralgias. The patient was hypothyroid,
the most likely cause of her positive ANA, in my view.
Everything else on history and examination was negative.
The patient was reassured, a few extra tests were done and
found to be negative (RF3, ENA4, anti-dsDNA5 and urinalysis),
and the patient was sent back to primary care. In
neither case did I suggest serial testing of the abnormal
lab parameters.
I don’t lose sleep over isolated lab abnormalities, but patients
and primary care physicians seem to be more troubled
by the perceived uncertainty engendered by red numbers
on the lab results tab in the electronic medical record
(EMR). Patient lab portals have led to increased queries
about abnormalities of the RDW6, MCH7, and other tests
which are not specifically requested, but for which results
are received nevertheless. The lab macro that accompanies
every positive ANA doesn’t help: “could be a sign of …”
Medicine is all about dealing with uncertainty, as is
life in general. The effects of a treatment, good or bad, are
based on probabilities. Evidence-based medicine is great,
but what about all the situations where there is no evidence
(rare disease, no randomized controlled trials) or the evidence
is in conflict (just look at recent COVID-19 vaccine
guidelines, for instance)? Patients still need to be treated
in the here and now, and decisions need to be made.
Can the “uncertainty principle” help us? Heisenberg’s
uncertainty principle in its standard form describes how
precisely we may measure the position and momentum of
a particle at the same time — if we increase the precision
in measuring one quantity, we are forced to lose precision
in measuring the other. Well, that may be true in quantum
mechanics, though hotly debated. No help with our
patients.
If ordering a test won’t change what you do, don’t order
it. Good advice. Once ordered and abnormal, that
lab result is like an itch that must be scratched, it seems.
Whether driven by the patient or the physician, that ANA
or CK is going to be repeated, often for no good reason.
Patient #2 turned up first. She had changed family
doctors and had complained again of mild fatigue and
arthralgias. The ANA recheck was positive again at a lower
titre of 1/160 speckled/homogeneous. I could see that
readily from my old records, and the general practitioner
(GP) could have found that in the government lab database
if they had looked. Nothing else had changed, and
my conclusion was the same. More reassurance provided
(“likely related to your thyroid; positive ANA is seen in 13-
15% of the general population”), no need to repeat the
ANA in future (“it will be positive for life”), and my usual
offer to reassess (“your family doctor can call me with any
questions; I am happy to see you again if the need arises”).
Interestingly, shortly before seeing me, the patient had
seen another rheumatologist, whose workup included negative
MRIs of both hands, which would not have occurred
to me, but every generation of rheumatologists has their
favourite test.
Patient #1 also eventually returned with their high CK.
Still asymptomatic, not on any medication, no link to strenuous
exercise, no family history of myopathy or neurologic
disorders, and no weakness, rash or interstitial lung
disease. Maybe this patient’s high CK was a function of
gender and race/ethnicity, though I am increasingly suspect
of that explanation, given all the recent revelations
about correcting eGFRs8 and PFTs9 based on such criteria.
Another round of reassurance for the GP, as the patient
was sure they were healthy and didn’t seem to need my
opinion on that matter.
As a counterexample, recent Patient #3 was a
51-year-old man referred by their GP on the advice of
an orthopedic surgeon, who evaluated the patient for recurrent
ankle and foot pain and found nothing to operate
on. The history was classic for gout, but the patient
said that had been ruled out by their GP, as the uric
acid level was always normal. Well, of course, it could be
normal during an acute attack, but the lab database revealed
levels of 530, 484 and 465 μmoles/L over the last
few years. The only problem was that the lab had set the
upper limit of normal at 512, nowhere near the optimal
or treat-to-target value of 360. So, in the EMR, the 484
and 465 values were shown in black (“normal”), not red.
The patient was relieved to find out he was no longer a
“medical mystery.”
Similarly, Patient #4 was referred for worsening osteoporosis.
A recent BMD10 provided sequential results
between 2000 and 2018. Interestingly, the actual BMD in
grams/cm2 was virtually the same at the start and end of
this long observation period. However, the column labelled
“BMD change” showed an unrelenting series of minus
signs. Obviously, something had gone wrong in the algorithm.
Otherwise, this would be analogous to the imaginary
Penrose stairs made popular by the artist MC Escher
and the movie "Inception," a staircase in which the stairs
make four 90-degree turns as they ascend or descend yet
form a continuous loop, so that a person could descend
them forever and never get any lower. I earned my consult
fee for figuring that out and congratulated the patient on
maintaining the same BMD despite aging by 18 years. No
treatment required!
A typical week at the office: uncertainty mitigated for
the first two patients, and certainty provided for the last
two patients. Medicine is always interesting.
Glossary:
1. CK: Creatine kinase
2. ANA: Antinuclear antibody
3. RF: Rheumatoid factor
4. ENA: Extractable nuclear antigen
5. Anti-ds DNA: anti-double-stranded DNA
6. RDW: Red Cell Distribution Width
7. MCH: Mean corpuscular hemoglobin
8. eGFR: Estimated glomerular filtration rate
9. PFT: Pulmonary function test
10. BMD: bone mineral density
Philip A. Baer, MDCM, FRCPC, FACR
Editor-in-chief, CRAJ
Scarborough, Ontario
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