When to start screening health
Do More Screening Tests Lead to Better Health? Choosing Wisely
hi my name is dr. Mike Evans and today
I'm wondering if more is better
specifically if more screening tests are
better I mean it kind of makes sense
it's just a test so it doesn't seem like
there'd be a big downside and it might
pick up something early so to explore
this question let's paint a picture so
you've been going to a family doc or a
GP for many years and when they see you
for an annual checkup they do a whole
bunch of tests I should point out now
that we're talking about screening the
kind of tests we do when you're symptom
free so if you did have symptoms say a
sudden onset of severe fatigue or it
hurts when you pee or you have a strange
lump that is a different story and we'd
be much more likely to order tests to
find out what's going on I'm also making
the assumption your average or low risk
so for example if you've been on a
chronic medication likely to cause
osteoporosis or if you have a strong
family history of a disease we might
take a different course of action I will
link you to some online risk assessment
tools below and at the end so that you
can see where your own risk is at so
let's say your doc always tested your
thyroid and your vitamin D levels a
chest x-ray and ECG tracing for your
heart tested you for osteoporosis maybe
your woman under 21 and you've had a Pap
test or in your 40s and had a
mammography ordered okay now imagine you
moved and switch to a new doctor and she
or he doesn't order any of the screening
tests in fact she doesn't even want you
to come in for an annual opting instead
to invite you for a prevention visit
every few years so you might wonder hmm
was my last doctor better more thorough
great question
so let's look at these tests one at a
time let's start with the one that is
most debated whether low risk women
should have screening mammography to
detect breast cancer in their 40s this
is a hot potato right now and the
subject of much debate something that
the number of lives saved are so small
that all the cost and effort in the high
rate of false alarms investigations
unnecessary biopsies etc are not worth
it for individuals and we should be
investing something with a better return
as a collective others feel that it's
the
best option we have that it's getting
better and the treating early could get
better treatment options they just feel
better knowing where they are at even
though they know mammograms aren't
perfect for me this last point is key
knowing that the tests aren't perfect we
want them to be black and white this
tells me whether I have or or don't have
the disease but as you learn as we walk
through these tests in fact they're all
about trade-offs while screening tests
can find illness it can also
misdiagnosed people as disease when they
are not or tells people they are fine
when they are not there's more precision
for high-risk people and less precision
for low-risk people we see this ripple
effect with mammograms possible earlier
diagnosis and treatment which is what
most of us picture I think but it's also
important to consider how you would
manage the much higher probability of a
false alarm and possibly triggering
invasive procedures to show in the end
it was nothing to be concerned about
understanding these possible
repercussions pretest is key I should
point out again here that if you do have
a lump or you are at higher risk
don't let this debate delay you from
having discussion with your healthcare
provider what family Doc's will tell you
is that we focus on the testing but it's
it's actually about the relationships I
know that sounds funny but if you have a
good relationship with your doc this
leads to screening that's more
personalized that takes into account
your values the science and your own
unique risk the prevention is partly
about the right screening but the bigger
game in town is you having healthy
behaviors and partnering with you to
make positive change in your life ok
let's look at some of the other tests in
our basket for some tests we simply
don't have the trial showing they are
effective these tests might be ordered
out of habit maybe because they can be
helpful in high-risk people so I would
say thyroid and ECG testing fit here a
2015 review in the annals of internal
medicine show not one single study that
directly assessed benefits and harms of
screening for thyroid dysfunction and
low risk people the United States
Preventive task force or the u.s. PTF
looked at what research data was
available and conclude that routine
screening is not recommended unless
there are symptoms and signs of thyroid
disease or you're pregnant there's a
screening electrocardiogram or ECG of
your heart making
difference.the resting ECG is
problematic as it sends a mixed message
approximately one third to one half of
individuals with a healthy heart have
ECG abnormalities approximately 30% of
individuals with proven heart disease
have a normal resting cg and most
coronary events occur in individuals
without resting ECG abnormalities the
u.s. PTF reviewed the science in 2012
and recommended against screening ECGs
if you are low risk for heart disease
next is measuring vitamin D levels in
the blood which is interesting
especially to us in the northern
latitudes of Canada and again I'm
talking about the average person not
somebody who has malabsorption kidney
disease or other risk factors I suppose
there are three pieces to the vitamin D
puzzle question number one is whether
vitamin D supplementation helps so
that's probably its own whiteboard but
but I would say that it's a one vitamin
left standing with smaller trials
showing benefit for bone heart health
cancer and so on on the other hand we
thought this about many other vitamins
and then larger high-quality randomized
control trial showed they actually
didn't help we are still waiting for
these larger trials of vitamin D second
is a test itself called 25 hydroxy
vitamin D there's some debate about the
test and considerable variation between
labs the ideal level of vitamin D in a
person's body has not been rigorously
established for the population in
general or for specific ethnic groups
finally there's a flipside approach and
that is instead of focus on testing we
focus on lifestyle change like eating
well and getting outside and if we are
at risk say in the winter or if we are
dark skinned or institutionalized
instead of testing we simply take a
vitamin D supplement now let's look at
osteoporosis again we are missing
high-quality research trials to tell us
exactly whom to screen but we also know
that osteoporosis related bone fractures
are common as we age women are at higher
risk and these fractures can cause loss
of Independence function and premature
death so expert groups mostly feel that
the two groups that will benefit from
screening with bone densitometry are one
women and men over 60
five and two people with one or more
risk factors such as having a low impact
fracture low weight we're matured
arthritis and so on see the risk
assessment tool for a longer list your
bone density score dictates how soon you
will have to do follow-up testing but
the key message is that once we have a
snapshot we get a better sense of your
bones if we leave some time in between
testing so for example if you are at low
risk you can actually wait five to ten
years sooner if you have risk factors
but most people can wait two years on to
our next test should you get a chest
x-ray well for people that have smoked a
pack a day for thirty years or more we
have emerging evidence in favor of a low
dose chest CT scan but as far as a chest
x-ray a large randomized trial of about
a hundred and fifty thousand men and
women aged 55 to 74 so that a single
view screening chest x-ray done every
year did not make a difference in the
number of people dying from lung cancer
so finally let's look at pap smears
where we take a swab from a woman's
cervix to check for cancer our story
here has changed
we should say we need to do a PAP
annually on all sexually active woman
now the science tells us that we're
getting many false alarms without
benefits for younger woman
the smarter strategy is to have a Pap
test at age 21 if you're sexually active
and if it's normal then repeat every
three years we stopped at age 70 but
only if there are no problems in the
previous ten years which means three
normal Pap tests okay hopefully you can
see with these various tests is some are
complicated so I'll have no evidence and
some need to be done but only for people
at higher risk or at longer time
intervals speaking of time intervals
even the concept of an annual physical
is not based in science it's not usual
practice outside of North America it's
easier for us to remember every year but
that doesn't mean it's best for our
health for example high risk people get
screened more often but optimal interval
screening for common lab tests like
cholesterol is every three to five years
or every three years for diabetes I
achieved mixed feelings about this I
love the opportunity to just focus on
prevention with my patients but like
most family Doc's I've shifted from
blind annual testing on everybody
towards customs to
jeez to consider your values and your
individual risk factors and encouraging
healthy behaviors like moving more
healthy eating helping people think
better and being opportunistic about
making positive change so as your new
family doc okay I would say so
by less testing she or he is likely
improving your house and applying signs
not only to treatment but to prevention
like a lot of things in life when we
think about it more isn't always better
better communication and knowing
yourself allow you to choose a little
more wisely hope this helps
