The document discusses a Patient Empowerment Program (PEP) talk on reading and interpreting laboratory test results. The talk aims to empower laypeople to understand the importance of laboratory tests in managing their health. It covers what laboratory tests are, the general types of tests (those with numeric values and those with narrative descriptions), and how to read and interpret test results, including looking at reference ranges and values and considering clinical context. The talk emphasizes correlating test results with a patient's symptoms, medical history and other relevant factors.

1. Empowerment
objective - for
laypeople to have an
understanding of
the importance of
reading and
interpreting
laboratory test
results in their
health management.
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
July 16, 2022
1400H - 1500H
Via Zoom

2. Empowerment
objective - for
laypeople to have an
understanding of
the importance of
reading and
interpreting
laboratory test
results in their
health management.
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
ROJoson PEP Talk
I have a Patient
Empowerment
Program in which I
like to empower the
lay people or
patients to take
control in the
management of
their health.

3. There are 3 courses
in the PEP Talk.
I completed the Core
Course on October 9,
2021.

4. From October 23,
2021 onwards, I have
been tackling Health
Disorder and Health
Issue Courses. This
may take 3 years or
longer.

5. Empowerment
objective - for
laypeople to have an
understanding of
the importance of
reading and
interpreting
laboratory test
results in their
health management.
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
My PEP TALK today
is entitled: Reading
and Interpreting
Laboratory Test
Results.
This is part of the
Health Issue Course.

6. Contents of PEP TALK on Reading and Interpreting
Laboratory Test Results
• What are laboratory tests?
• What are the general types of laboratory tests?
• How to read and interpret lab tests with
numeric values?
• How to read and interpret lab tests with
narrative description and conclusions?
• What are the issues on laboratory tests
especially on indications?
• Examples of dilemmas and errors in lab results
and interpretations
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results

7. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Backgrounder on Talk
A lot of Filipino patients have laboratory tests
done for one reason or another, usually resulting
from screening fad or ordered by physicians who
are ritualistic and maximalist.
Then, they ask me to read and interpret the
results.

8. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Backgrounder on Talk
I am a minimalist physician.
I don’t subscribe to the screening fad of laypeople
as well as physicians who are usually ritualistic
and maximalist and who outrightly want to please
their patients with their desire for screening
laboratory tests.

9. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Backgrounder on Talk
I do laboratory tests only when indicated
(patients with symptoms and signs in which I am
not very definite with my clinical diagnosis that I
need help from laboratory tests; patients without
symptoms and signs but with a high risk for a
particular disease).

10. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Backgrounder on Talk
In my practice, I cannot avoid or refuse patients
coming to me for interpretation of the results of
their laboratory tests requested by themselves
and other physicians.
Because of the prevalence of these events, I have
decided to try to write something about them,
particularly to advise the laypeople on how to
read and interpret the results of the laboratory
tests.
I like to empower the
patients to know the
principles and
processes and
caveats of reading
and interpreting lab
test results.
Along the way,
hopefully, I can
convince them to
have lab tests done
only when indicated.

11. • What are laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
To start with, laboratory tests are diagnostic tests
to determine if there is /are abnormalities
present or not in the tests done on patients.

12. • What are laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
The basic definition of laboratory tests is that
they are diagnostic tests done on part or whole of
a patient’s body performed in a “laboratory
setting” where there is a controlled environment
with appropriate equipment, supplies, and
available certified expertise.

13. • What are laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
With the advent of so many kinds of diagnostic
tests being done and promoted (not to say
commercialized), the “laboratory setting” has
expanded from one that examines samples of
patients’ blood, urine, fluid or tissue to radiology
centers, nuclear imaging centers, MRI centers, PET
scan centers, endoscopy centers, etc.

14. • What are laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Thus, diagnostic reports are coming from these
various kinds of laboratory centers. The
diagnostic reports will be based on the parts of
the patients’ body being examined and the type
or technique of doing the diagnostic tests.

15. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Essentially, results from diagnostic reports can be
categorized into two general types:
1) whether they contain numeric values that will
denote normality or abnormality and
2) whether they contain a narrative description
and interpretation by a certified reader of
what was seen or so-called findings, which
also denote normality or abnormality, and if
abnormal, possible diagnosis / diagnoses are
given.

16. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Examples of laboratory tests with diagnostic
reports containing numeric values denoting
normality or abnormality:
• Complete Blood Count (CBC)
• Metabolic Panel
• Lipid Panel
• Thyroid Function Tests

17. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Complete Blood Count (CBC)

18. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Metabolic Panel

19. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Metabolic Panel
Glucose 70 to 100 mg/dL
Calcium 8.5 to 10.2 mg/dL
Sodium 135 to 145 mEq/L
Potassium 3.7 to 5.2 mEq/L
Bicarbonate 23 to 29 mEq/L
Chloride 96 to 106 mEq/L
Blood Urea Nitrogen (BUN) 6 to 20 mg/dL
Creatinine 0.6 to 1.3 mg/dL

20. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Metabolic Panel
Albumin 3.4 to 5.4 g/dL
Total Protein 6.0 to 8.3 g/dL
Alkaline Phosphatase (ALP) 20 to 130 U/L
Alanine Aminotransferase (ALT) 4 to 36 U/L
Aspartate Aminotransferase (AST) 8 to 33 U/L
Bilirubin 0.1 to 1.2 mg/dL

21. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Lipid Panel

22. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Thyroid Function Tests

23. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Examples of laboratory tests / exams with a
narrative description and interpretation by a
certified reader of what was seen or so-called
findings, which also denote normality or
abnormality, and if abnormal, possible diagnosis /
diagnoses are given:
• X-ray reports
• Ultrasound reports
• CT scan / MRI reports
• Others

24. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• X-ray reports
Showing the narrative
description of findings
and conclusion or
"impression."

25. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Ultrasound reports
Showing the narrative
description of findings
and conclusion or
"impression."

26. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• CT scan reports
Showing the narrative
description of findings
and conclusion or
"impression."

27. • What are the general types of laboratory tests?
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• NOTE: some diagnostic reports have
combination of numeric values and
narrative descriptions.
URINALYSIS
•Color – Yellow (light/pale to dark/deep
amber)
•Clarity/turbidity – Clear or cloudy
•pH – 4.5-8
•Specific gravity – 1.005-1.025
•Glucose - ≤130 mg/d
•Ketones – None
•Nitrites – Negative
•Leukocyte esterase – Negative
•Bilirubin – Negative
•Urobilirubin – Small amount (0.5-1 mg/dL)
•Blood - ≤3 RBCs
•Protein - ≤150 mg/d
•RBCs - ≤2 RBCs/hpf
•WBCs - ≤2-5 WBCs/hpf
•Squamous epithelial cells - ≤15-20
squamous epithelial cells/hpf
•Casts – 0-5 hyaline casts/lpf
•Crystals – Occasionally
•Bacteria – None

28. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Some information on diagnostic reports with
numeric values
These reports contain numbers that will denote normal
values.
The values serve as a reference for physicians or patients to
interpret the test results.
Numbers can come in range or the so-called reference
range, such as 10 to 15 or just one number including zero.
For the latter, the one number may be the cut-off value of
normality or abnormality. For example, the cut-off is 300
and there is a stipulation that any value below 300 is
normal and any value at 300 and above is considered
abnormal.

29. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Some information on diagnostic reports with
numeric values
Thus, in laboratory tests with
diagnostic reports containing
numeric values, one will and
should see two columns: the
reference values and the
results.
If the reference values contain
conventional and SI
(International system of Units)
values, then they are more
columns. But basically, TWO.

30. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Some information on diagnostic reports with
numeric values
The reference range is a set of values that
includes upper and lower limits of a lab
test based on a group of otherwise
healthy people. It is based on the results
that are seen in 95% of the healthy
population.

31. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Some information on diagnostic reports with
numeric values
Not all lab results that fall outside the
reference range or values are truly
abnormal. They may still be normal. They
may be false positives.
Sometimes patients whose test results
are outside of the reference values may
be healthy, and some patients whose test
results are within the reference values
may have a health problem.

32. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Some information on diagnostic reports with
numeric values
Also, the reference values for a
test may be different for
different groups of people (for
example, men and women).

33. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Some information on diagnostic reports with
numeric values
Lastly, one has to know that different laboratories
may be using different reference ranges.
This may be due to differences in lab testing
equipment, chemical reagents, and analysis
techniques.
To interpret the results, one just has to rely on the
reference ranges or values provided by the
laboratories where the tests are done.

34. • How to read and interpret laboratory tests / exams with
diagnostic reports containing numeric values
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• First, look at results.
• For the laboratory tests
/ exams with reference
ranges (normal values),
see if the results fall
within the reference
ranges.

35. • How to read and interpret laboratory tests / exams with
diagnostic reports containing numeric values
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• First, look at results.
• For the laboratory tests / exams with reference ranges
(normal values), see if the results fall within the
reference ranges.

36. • How to read and interpret laboratory tests / exams with
diagnostic reports containing numeric values
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• If they do, (results falling within the reference ranges)
then they are usually interpreted as normal BUT make
sure the patients have no symptoms or signs of a
medical condition or disease associated with the tests
done. If the patients have symptoms or signs, the result
may be false negative.
• A repeat test or another more sophisticated or higher-
level test may be done to ensure that a false negative
result is not present.

37. • How to read and interpret laboratory tests / exams with
diagnostic reports containing numeric values
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• If the results are not within the reference
range, a red flag is raised but they have to be
interpreted properly before considering them
as abnormal.

38. • How to read and interpret laboratory tests / exams with
diagnostic reports containing numeric values
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• First, one has to look at the degree of deviation
from the normal reference ranges. The greater
the degree of deviation, the greater the chance
for abnormality. If there is a small degree of
deviation, chances are the out-of-range values
can still be considered normal.
• A dilemma exists: there are no established
rules that would say that if this or that degree
of deviation is present, it should automatically
be considered abnormal or still normal. It will
be a judgement call by the physicians.

39. • How to read and interpret laboratory tests / exams with
diagnostic reports containing numeric values
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• The second thing one has to do is to see if
there are symptoms and signs indicative of a
true medical condition or disease being
present and, if present, whether the test with
an out-of-range values is pointing to it. If yes,
the out-of-range value should be considered
abnormal even if the degree of deviation is
slight or small. If no, the out-of-range value
can be considered normal, particularly if the
degree of deviation is slight or small.

40. • How to read and interpret laboratory tests / exams with
diagnostic reports containing numeric values
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• If the degree of deviation is big, even without
symptoms and signs, abnormality should
strongly be considered.
• Again, the dilemma, the cut-off for small and
big degree of deviation is not established – 5%,
10%, 15%, or 20% higher than the upper limit
of the range or lower than the lower limit of
the range – NOT ESTABLISHED YET. Probably,
20% higher or lower is definitely significant.

41. • How to read and interpret laboratory tests / exams with
diagnostic reports containing numeric values
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• It has to be emphasized that it is not simply
comparing the reported diagnostic results with
the reference values or ranges.
• One has to correlate the results with the
patients’ other medical data, such as presence
or absence of symptoms; if present, what are
they; what are physical examination findings; is
the patient taking medicines before the tests;
are there other tests done; and other
circumstantial situations.

42. • How to read and interpret laboratory tests / exams with
diagnostic reports containing numeric values
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• When interpreting diagnostic results with
numeric values, especially ranges, one has
to take note that the laboratory sets
“normal” ranges for laboratory tests based
upon population studies.
• Standard “normal” ranges for tests with
numeric values are based upon use of a
bell shaped curve. “Normal” is usually
defined as those test values that fall within
2 standard deviations of the mean, which
includes 95% of all results.

43. • How to read and interpret laboratory tests / exams with
diagnostic reports containing numeric values
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• So, there is a 1 in 20 or 5% chance that an
“abnormal” test may really be normal. In
other words, about 5 percent of the
healthy population land somewhere
beyond this “normal” range. That’s why
not all which fall outside the “normal”
range are automatically abnormal. The
physician has to come in to make a
decision.

44. • How to read and interpret laboratory tests / exams with
diagnostic reports containing narrative description and
interpretation by a certified reader of what was seen or
so-called findings
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• My recommendations:
• You can take a look and read the contents if you
want. However, as a layperson, chances you will not
understand and more so, interpret the narrative
descriptions and conclusions of the certified readers. So,
have the narrative diagnostic reports read and
interpreted by a physician-clinician or your attending
physician and let him / her make a decision on the
report.

45. • How to read and interpret laboratory tests / exams with
diagnostic reports containing narrative description and
interpretation by a certified reader of what was seen or so-
called findings
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Even for the physician-clinicians or attending physicians,
they have to interpret the words or phrases used by the
certified readers and to read between the lines.
• In addition, they have to correlate the findings and
conclusions of the readers with the symptoms and signs,
other tests and other circumstantial situations that a
patient may have to make a decision whether everything
is normal; a finding is a mere biological variation;
something abnormal is being suspected; and/or there is
really an abnormality going on.

46. • How to read and interpret laboratory tests / exams with
diagnostic reports containing narrative description and
interpretation by a certified reader of what was seen or so-
called findings
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• At times, they have to check the accuracy of the reports
and may have to have discussion with the readers of the
narrative diagnostic reports.

47. • How to read and interpret laboratory tests / exams with
diagnostic reports containing narrative description and
interpretation by a certified reader of what was seen or so-
called findings
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• In practically all the narrative diagnostic
reports, there is usually a caveat statement
that runs like this: “This result is best
interpreted by your attending physician in
correlation with your clinical data, imaging and
other laboratory results.”

48. • How to read and interpret laboratory tests / exams with
diagnostic reports containing narrative description and
interpretation by a certified reader of what was seen or so-
called findings
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Another statement to the same effect: “This
radiologic interpretation is only a part of the
overall assessment of a patient’s condition. It
must be correlated with the clinical, laboratory
and other ancillary parameters for a
comprehensive analysis. Therefore, radiology
reports are best explained by the attending
physician to the patient.”

49. • How to read and interpret laboratory tests / exams with
diagnostic reports containing narrative description and
interpretation by a certified reader of what was seen or so-
called findings
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Another important thing to do when a
layperson reads a narrative diagnostic report
that contains a recommendation statement on
additional diagnostic tests or procedure or on
repeat surveillance tests after so many months
is just to consider it as a recommendation.

50. • How to read and interpret laboratory tests / exams with
diagnostic reports containing narrative description and
interpretation by a certified reader of what was seen or so-
called findings
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results

51. • How to read and interpret laboratory tests / exams with
diagnostic reports containing narrative description and
interpretation by a certified reader of what was seen or so-
called findings
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Your attending physician or clinician-physician
should be the one to decide what to do next
after interpreting the report, after re-
examining you and after correlating it with
other clinical data. He may or may not follow
the recommendation of the certified readers of
the narrative diagnostic reports.

52. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• At the end of the day, after receiving your
diagnostic reports whether with numeric
values or narrative description and
conclusions, you can read them if you wish but
follow the principles, processes and caveats on
interpretation mentioned above but your
attending physicians or physician-clinicians will
have the last say on conclusion (whether
abnormality is present or not or doubtful
findings) and on what to do next (such as
repeat or no need to repeat the tests
anymore).

53. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• After hearing the explanations and
recommendations on what to do next by your
attending physician, feel free to ask questions
as needed for further clarifications. The
decision on what to do next should be a shared
one between you and your attending
physician.

54. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• If there is a need for a second opinion from
another physician on the conclusion and
recommendations on what to do next, go
ahead. You have the right to seek a second
opinion. This is part of patient empowerment.
Knowing the principles and processes of
reading and interpreting laboratory tests and
their associated caveats is also part of patient
empowerment.

55. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
There are a lot of issues in laboratory testings and
results.
• Foremost issue is the too many lab tests being
done and many of which
• are usually not necessary
• have results, especially alarming ones that
• are difficult to interpret
• have led to a cascade of other tests
• have caused undue patients’ anxieties
• have led to unnecessary and erroneous
treatment
• Have caused other undue harms
• Have caused unnecessary expense
• Have wasted limited healthcare resources

56. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Indications for laboratory tests:
• To screen for a disease or exclude its
presence
• To have a more definite diagnosis after
clinical evaluation
• To determine severity of a disease present
and to prognosticate (to project outcome)
• To monitor progress of disease and
treatment

57. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Indications for laboratory tests:
• To screen for a disease or exclude its
presence
• To have a more definite diagnosis after
clinical evaluation
• To determine severity of a disease present
and to prognosticate (to project outcome)
• To monitor progress of disease and
treatment
Valid indications for
screening:
• Mandated by law
– e.g. Newborn
Screening
• Occupational,
travel, and
organizational
requirements
• High risk for a
particular medical
condition or
disease

58. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Indications for laboratory tests:
• To screen for a disease or exclude its
presence
• To have a more definite diagnosis after
clinical evaluation
• To determine severity of a disease present
and to prognosticate (to project outcome)
• To monitor progress of disease and
treatment
Valid indications for
more definitive
diagnosis:
• Uncertainty in
clinical diagnosis
• More definite
diagnosis is
needed to plan
out a specific
treatment
regimen,
especially one
that is complex

59. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Indications for laboratory tests:
• To screen for a disease or exclude its
presence
• To have a more definite diagnosis after
clinical evaluation
• To determine severity of a disease present
and to prognosticate (to project outcome)
• To monitor progress of disease and
treatment
Valid indications for
determining severity
of a disease and
prognosis:
• Timing of
treatment will be
affected.
• Treatment plan
will be affected
such as palliative
/ hospice care in
patients with
poor prognosis

60. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Indications for laboratory tests:
• To screen for a disease or exclude its
presence
• To have a more definite diagnosis after
clinical evaluation
• To determine severity of a disease present
and to prognosticate (to project outcome)
• To monitor progress of disease and
treatment
Valid indications for
monitoring progress of
disease and treatment
• To get to a more
definitive diagnosis
• To know the outcome
of disease and also of
the treatment
• To institute new or
additional treatment
as indicated

61. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Indications for laboratory tests:
• To screen for a disease or exclude its
presence
• To have a more definite diagnosis after
clinical evaluation
• To determine severity of a disease present
and to prognosticate (to project outcome)
• To monitor progress of disease and
treatment
Lack of valid
indications leads to
SCREENING FAD or
CRAZE and
INAPPROPRIATE
USAGE.

62. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
What is an inappropriate or unnecessary test?
It can be defined as any test where the results are
not likely to be medically necessary for clinical
management of the patient.

63. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
What is an inappropriate or unnecessary test?
It can be defined as any test where the results are
not likely to be medically necessary for clinical
management of the patient.
Valid indications for
screening:
• Mandated by law
– e.g. Newborn
Screening
• Occupational,
travel, and
organizational
requirements
• High risk for a
particular medical
condition or
disease
Outside the stipulated valid
indications, all lab tests done are
considered inappropriate or
unnecessary.

64. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
A common practice is SHOTGUN approach – using
a shotgun (all possible lab tests upfront) to hit the
bull’s-eye. – NOT RECOMMENDED.
Use a RIFLE approach in ordering lab tests to hit
the diagnosis being suspected. – RECOMMENDED.

65. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Risks of Unnecessary Laboratory Testing
• Tests ordered indiscriminately may produce results out
of the normal range without disease, and lead to
additional unnecessary testing.
• Patient risk is increased from performing unnecessary
tests since every procedure carries some risk and
unnecessary therapeutic measures with potential
adverse outcomes may be instituted.
• If laboratory tests are ordered without sufficient
indication, then monetary and personnel resources are
wasted.

66. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Risks of Unnecessary Laboratory Testing
• Inappropriate laboratory test ordering leads to
a higher probability of false-positive abnormal
results. False-positive test results are harmful
psychologically and financially to the patients
and to the health care system, respectively.
• More than half of abnormal results from
laboratory tests ordered by family physicians
could be false-positive (Canada, 2018 Can Fam
Physician. 2018 Mar; 64(3): 202–203.)

67. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
“Laboratory Errors”
• Laboratory error is defined as “any defect from
ordering tests through reporting results, as
well as appropriately interpreting and reacting
to them”.
• An error in the clinical laboratory may occur
during the pre-analytical, analytical, or post-
analytical phases; this entire process is
impossible to perform error-free. Any
laboratory analysis strives to reduce
uncertainty and estimate their magnitude to
an acceptable degree.

68. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
“Laboratory Errors”
• Pre-analytical components are defined as steps
beginning with the clinician's request and including the
examination requisition, patient preparation, collection
of the primary sample, transportation to and inside the
laboratory, and ending when the analytical examination
procedure begins.
• Post-analytical components are defined as processes
that occur after the examination, including systematic
review, formatting and interpretation, authorization for
release, reporting and transmission of results, and
storage of examination samples.
The analytical
component begins
when the patient
specimen is
prepared in the
laboratory for
testing, and it ends
when the test
result is interpreted
and verified by the
technologist in the
laboratory.

69. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
“Laboratory Errors”
• Errors can occur at any stage and result in an
inaccurate report production, which can have
an impact on patient care such as misdiagnosis
and incorrect treatment.
• The most common errors impacting laboratory
test findings occur in the pre-analytical phase
(46–68.2% of total errors) and post-analytical
phase (18.5–47% of total errors), with less (7–
13% of total errors) occurring in the analytical
phase.

70. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Results vis-a-vis the reference ranges
• If within, one is still not 100% certain that the
results are all normal, even the patients do not
have symptoms of a diseases. They may be
false-negative. They may be laboratory errors
and circumstantial situations in the patients
such as medicines taken and biologic variations
that made them fall within the range.
• NORMAL RESULT IS NOT ALWAYS NORMAL.
However, most of
the time, those
results falling
within the range
are considered
normal especially if
there are no
symptoms of a
disease.

71. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Results vis-a-vis the reference ranges
• If outside, is it outrightly abnormal? NO. But
somebody will have to decide on this, usually
the attending physicians. They go by some
guidelines and some gut-feel. That’s why
nothing is absolutely certain also.
• The result may be a product of laboratory
errors, circumstantial situations like foods and
medicines taken and biologic variations. The
physicians decide on what to do.
• ABNORMAL RESULT IS NOT ALWAYS
ABNORMAL.
However, most of
the time, those
results falling
outside the range
are still considered
normal especially if
the degree of
deviation is small
and if there are no
symptoms of a
disease.

72. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Indications for laboratory tests:
• To screen for a disease or exclude its
presence
• To have a more definite diagnosis after
clinical evaluation
• To determine severity of a disease present
and to prognosticate (to project outcome)
• To monitor progress of disease and
treatment
High incidence of results
outside the range – more
than 50%!
Hard to explain the cause!
May be due to:
• laboratory errors
• Circumstantial
situations
• Biologic variations
• Etc.
Difficult to decide with
certainty!
Thus, advise to avoid
doing lab tests without
good indications.

73. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Remember, the more tests you do the more likely
you are to get at least one 'false positive' outside
the laboratory reference range.
Aim to limit the number of tests to those that are
relevant to the clinical situation rather than
requesting a screening battery.
High incidence of results
outside the range – more
than 50%!
Hard to explain
May be due to:
• laboratory errors
• Circumstantial
situations
• Biologic variations
• Etc.
Difficult to decide with
certainty!
Thus, advise to avoid
doing lab tests without
good indications.

74. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Examples of dilemmas and errors in lab results
and interpretations
• There are plenty of personal examples but I will
just cite about 6 for this PEP Talk.
• I will amplify on these dilemmas and errors in
lab results and interpretations in future PEP
Talk.

75. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Examples of dilemmas and errors in lab results
and interpretations
• OUT-OF-RANGE NUMERIC VALUES
CBC, Urinalysis, Lipid Profile

76. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Normal Hemoglobin Levels by Age and Gender Chart
Ages and Genders Normal Hemoglobin Levels (gm/dL)
Newborn 17 - 22
One (1) week 15 - 20
One (1) month 11 - 15
Children 11 - 13
Adult Males 14 - 18
Adult Women 12 - 16
Men After Middle Age 12.4 - 14.9
Women After Middle Age 11 - 13.8
Interpretation –
If Hgb is 10 – really abnormal unless the
patient is pink, then may be lab error.
If Hgb is 13 – may still be normal and
acceptable – does not have to treat
Ill-effects:
• Anxiety of patients
• Cascade of tests by physicians

77. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
WBC in Urinalysis
Normal – less than 5 / HPF
If more than 10 / HPF – really abnormal unless
the urine is erroneously collected (not mid-
stream)
If 7 / HPF – may still be normal and acceptable,
especially if with no symptoms – observe and
does not need treatment
Ill-effects:
• Anxiety of patients
• Cascade of tests by physicians

78. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Total cholesterol
Total cholesterol levels under 200 mg/dl are
healthy for adults.
Doctors treat readings of 200–239 mg/dl as
borderline high, and readings of at least 240
mg/dl as high.
Ill-effects if result is 205 mg/dl:
• Anxiety of patients
• Cascade of tests by physicians
• Medications prescribed
• May still be normal
• May repeat test

79. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Examples of dilemmas and errors in lab results
and interpretations
• THYROID FUNCTION TESTS

80. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
ZG, 66-year-old female, had thyroid function tests done as
screening (not ordered by me). NO symptoms of
hyperthyroidism or hypothyroidism.
FT3 low; FT4 normal; TSH elevated. I asked for a repeat.

81. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Repeat tests – normal FT3; normal FT4; and
normal TSH.

82. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
ZG, 66-year-old female, had thyroid function tests done as
screening (not ordered by me). NO symptoms of
hyperthyroidism or hypothyroidism.
FT3 low; FT4 normal; TSH elevated. I asked for a repeat.
Repeat tests – normal FT3; normal FT4; and normal TSH.
If there were NO repeat tests, patient could have been
treated unnecessarily with medications, which can be
lifetime. She has normal thyroid function tests afterall.
She will have the unwanted lifetime anxiety of thinking she
has a thyroid disease.
Also, she may have a cascade of other unnecessary tests like
ultrasound and biopsy that may be needed to do further
investigations.
Fortunately, for her, a repeat test has prevented these
errors and other possible negative consequences.

83. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Examples of dilemmas and errors in lab results
and interpretations
• BREAST ULTRASOUNDS

84. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
AD, 61-year-old female, had a breast ultrasound and
mammogram for screening. NO symptoms. NO palpable
breast mass.
Initial report in one hospital: BIRADS 4 – suspicious for
malignancy.
Repeat test: BIRADS 3 – probably benign.

85. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results

86. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results

87. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
AD, 61-year-old female, had a breast ultrasound and mammogram
for screening. NO symptoms. NO palpable breast mass.
Initial report in one hospital: BIRADS 4 – suspicious for malignancy.
Repeat test: BIRADS 3 – probably benign.
If there were NO repeat tests, patient could have undergone
an unnecessary operation. She was indeed scheduled for
the operation but sought second opinion.
She would have the unwanted anxiety of thinking she has a
breast cancer.
Also, she may have a cascade of other unnecessary tests like
that may be needed to do further investigations.
Fortunately, for her, one repeat test has prevented this error
and other possible negative consequences.

88. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Examples of dilemmas and errors in lab results
and interpretations
• GALLBLADDER ULTRASOUNDS

89. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
AC, 55-year-old male, complained of difficulty of urination.
A whole abdomen ultrasound was done. Aside from the
enlarged prostate, gallbladder stones were reported and he
was advised gallbladder surgery.
He sought second opinion from me. I asked for a repeat
ultrasound in another institution. Repeat test showed
gallbladder polyp which does NOT need an operation. Even
if the repeat test showed gallbladder stones, since he was
not symptomatic as far as the stones are concerned,
operation is still not needed, just observe and monitor.

90. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
First ultrasound

91. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Repeat ultrasound
First ultrasound – Gallbladder stones
Repeat ultrasound – Gallbladder polyp

92. Contents of PEP TALK on Reading and Interpreting
Laboratory Test Results
• What are laboratory tests?
• What are the general types of laboratory tests?
• How to read and interpret lab tests with
numeric values?
• How to read and interpret lab tests with
narrative description and conclusions?
• What are the issues on laboratory tests
especially on indications?
• Examples of dilemmas and errors in lab results
and interpretations
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Summary
Take Away

93. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Although the reports are written for healthcare
professionals, not patients, there is a lot you can
learn by looking, studying, and learning from
them (especially after this PEP Talk).

94. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
• Indications for laboratory tests:
• To screen for a disease or exclude its
presence
• To have a more definite diagnosis after
clinical evaluation
• To determine severity of a disease present
and to prognosticate (to project outcome)
• To monitor progress of disease and
treatment
High incidence of results
outside the range – more
than 50%!
Hard to explain the cause!
May be due to:
• laboratory errors
• Circumstantial
situations
• Biologic variations
• Etc.
Difficult to decide with
certainty!
Thus, advise to avoid
doing lab tests without
good indications.

95. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
A common practice is SHOTGUN approach – using
a shotgun (all possible lab tests upfront) to hit the
bull’s-eye. – NOT RECOMMENDED.
Use a RIFLE approach in ordering lab tests to hit
the diagnosis being suspected. – RECOMMENDED.

96. • Issues in Laboratory Testings and Results
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
It's important to treat the patient and not the lab
value.
Nowadays, this concept is fading.
Physicians commonly do not do clinical
assessment of patients anymore. They just look
and rely on lab test results without doing physical
examination of the patients.
Lab results should be correlated with clinical
findings (history and physical examination).

97. Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results
Take Away in
relation to
Patient
Empowerment
Be always in touch with reliable medical
information on how physicians read and interpret
laboratory tests.
Knowledge is power; it gives power.
Use the 4Ks of Patient Empowerment:
Kaalaman, Kakayanan, Karapatan and
Kapangyarihan
to gain greater control over decisions in
medical management of oneself by having
some idea on how physicians read and
interpret diagnostic tests.

98. Empowerment
objective - for
laypeople to have an
understanding of
the importance of
reading and
interpreting
laboratory test
results in their
health management.
Health Issue
Course–
Reading &
Interpreting
Laboratory Test
Results