While technology advances, there seems to be
a major decline in medical education, generally. By medical education, of
course, I do not mean the university education or training of medical
personnel. I rather mean the quantity of ADEQUATE medical information available
to the common man.
Subsequently, because many do not have adequate
information, they simply go with the flow. One of such is the fact that once a
test result is given, a person is made to believe that it is equated with some
diagnosis of an ailment. But this isn’t true.
This is one of the reasons many patients
abhor the thought of running a test to establish the proper diagnosis for some frequently
presenting symptoms. This shouldn’t be so, either.
The truth is, a “positive test”
does not always equal “a disease” and a “negative test” does not always equal “no
disease.” The “positive test = disease”
and “negative test = no disease” is a common trap that
many have fallen into.
In essence, that a test comes out
positive should not immediately give you a reason to worry. On the other hand,
that a test comes out negative should not immediately give you a reason to
discard the apparent symptoms and rest on your oars. The whole scenario and
possible outcomes rise and fall on the experience of the consulting physician.
It is important to state that no test is 100% accurate. Therefore, it is
essential when ordering a test that the attending physician has some knowledge
of the test’s characteristics, as well as how to apply the test results to an individual patient’s clinical situation.
As an example, when a patient presents with
chest pain, the first diagnostic concern for most doctors and patients is angina pectoris, that is, the pain of myocardial ischemia caused by coronary insufficiency.
However, in making the diagnosis of angina
pectoris, the clinician must be able to establish whether the pain satisfies
the three criteria for typical anginal pain:
(1) Retrosternal in location,
(2) Precipitated by exertion, and
(3) Relieved within minutes by rest or
nitroglycerin.
Other factors such as the patient's age and some
risk factors can then be taken into consideration.
To put this in perspective with this article,
let us consider the example of a 21-year-old woman with chest pain that is not
exertional and not relieved by rest or nitroglycerin.
This patient has a very low probability of
coronary artery disease. Thus, any positive results on a cardiac stress test
are very likely to be false positives. As a matter of fact, this test result is
unlikely to change her management, and therefore, should not be obtained in the
first place.
Consequently, if you were this 21-year-old
woman, a positive test result on a cardiac stress test should not immediately
give you reasons to worry. Your doctor should be able to analyze your situation
properly and let you know that this test shouldn’t have been ordered in the
first instance, and that any “positivity” indicated may not be applied to your
situation.
The point here is that you shouldn’t
immediately get engrossed with a positive test result and begin to worry
unnecessarily, as the result is still subject to further scrutiny or clinical
evaluation in the light of your presenting symptoms, health history, and other factors.
Let us consider another example of a
69-year-old diabetic smoker with a recent coronary angioplasty who presents
with recurrent episodes of typical angina. Are there any reasons for this
patient to relax from the negative result of a cardiac stress test? Of course,
not.
With her history and presentation, it is
clear that this might be the pain of myocardial ischemia. A negative cardiac
stress test is likely to be falsely negative. Thus, the clinician should lay
aside this test result and proceed directly to a coronary angiography to assess
for a repeat angioplasty.
The whole point in this is, your
doctor knows something about the characteristics of the test employed in your
disease condition that you may not know. He also knows how to apply the test
results to your present health circumstances to reach a correct diagnosis.
Do not run to a hasty conclusion based
on your test result and dash off to a pharmacy store or begin to worry about
the possible outcomes for your health. Always remember, “positive test = disease” and “negative test = no disease” is a common trap that you
shouldn’t fall into. The analyses and diagnoses may be completely different
from what the results say.
Tests do not make diagnoses;
doctors do, considering test results quantitatively in the context of their
clinical assessment.
