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A.
Identification |
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Using a ball-point pen, write patient name, age, address,
phone number, sample collection date and physician
name on the front of the slide in the space provided.
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B.
Preparing the Test |
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Using
the applicator provided, collect a small
fecal sample.
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Apply a
thin smear covering Box
A.
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Reuse the
applicator to obtain a second sample from
a different part of the stool.
Apply a thin smear covering
Box B.
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Close the
cover flap. Dispose of applicator in a
waste container.
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If testing
immediately, wait 3 to 5 minutes
before developing. Otherwise, store slides
as directed for up to 14 days until ready
to develop. |
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C.
Developing the Test |
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Open
the back of the slide and apply two
drops of Hemoccult Developer
to guaiac paper directly over each smear.
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Read
results within 60 seconds. Any
trace of blue on or at the edge of the
smear is positive for occult blood. |
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D.
Developing the Performance Monitors®
Feature (Quality Control) |
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The
Performance Monitors areas must be developed
on every slide.
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Apply one
drop of Hemoccult Developer between
the positive and negative Performance Monitors
areas.
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Read
results within 10 seconds. If
the slide and developer are functional,
a blue color will appear in the positive
Performance Monitors area and no blue will
appear in the negative Performance Monitors
area.
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Neither
the intensity nor the shade of the blue
from the positive Performance Monitors
should be used as a reference for the
appearance of positive test results.
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Any blue
originating from the positive Performance
Monitors area should be ignored when reading the
sample test results |
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Reduce
False Positive Results Caused by Raw Fruits and
Vegetables |
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It is recommended to wait at least three days
from the date the last stool sample was collected
to develop the test. Waiting three days before
developing the test reduces plant peroxidase
activity in the stool sample and therefore the
rate of false positives.
By following this procedure your patients can
consume raw fruits and vegetables without affecting
test results.8-10
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Follow-up
on a Positive FOBT |
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A positive FOBT places a patient at high risk
for CRC and alerts the physician to do further
diagnostic testing.
The ACS recommends following a positive FOBT
with a study of the entire colon, whether by
colonoscopy or DCBE.
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Expected
Results |
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In a general screening population of highly
compliant asymptomatic individuals, the Hemoccult
test will yield a positivity rate of approximately
2 to 5%. The false-positivity rate in such a
population would be approximately 1 to 2%.15
Positivity rates for fecal occult blood
tests have been shown to vary in each patient
population depending on diet, age, predisposition
to colorectal disease, and other factors that
may be associated with bleeding gastrointestinal
lesions.14,16
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References:
(from Hemoccult Product Instructions (768k) )
8.
Sinatra, M.A. et al.: "Interference of
plant peroxidases with guaiac-based fecal occult
blood tests is avoidable," Clin. Chem.
45 (1):123-126, 1999.
9. Anderson,
G.D. et al.: "An investigation into the
effects of oral iron supplementation on In
Vivo Hemoccult stool testing," Am. J.
Gastroenterol. 85:558, 1990.
10. Clapp, W.H.
"Iodine and occult blood testing."
Consultant. 208, April 1984.
14. Young, G.P.,
and St. John, D.J.B., "Selecting anoccultblood
testfor use as a screening tool for large
bowel cancer," in: Rozen, P., ed., Front.
Gastrointest. Res. Basel, Karger. 18:135-156,
1991.
15. Data on file,
Product Development department, Beckman Coulter,
Inc., Primary Care Diagnostics (formerly SmithKline
Diagnostics, Inc.)
16.
Stanley, A.J., and St. John, D.J.B., "Faecal
occult blood test screening for colorectal
cancer - What are we waiting for?" Aust.
NZ J. Med. 29:545-551, 1999.
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