COST CONCIOUSNESS PROJECT
FECAL OCCULT BLOOD TEST (FOBT) –
APPROPRIATE OR NOT APPROPRIATE?
by Kelvin Nguyen
05/10/2013
BACKGROUND
• Fecal occult blood test is ordered in outpatient setting for colorectal cancer
screening.
• The test is ordered in the in-patient setting, many times for reasons not
related to colorectal cancer screening.
• Currently, fecal occult blood test can be done via 3 types of testing:
• Stool guaiac test for fecal occult blood (gFOBT) – detects heme
• HemoQuant – can quantify the heme moiety of intact hemoglobin
• Fecal DNA test – extract DNA from stool sample and testing for alteration
associated with cancer.
• Fecal Immunochemical testing (FIT) – specific antibodies detecting
globin – more specific for lower GI bleed.
UCI has been using gFOBT and recently having FIT test available.
BACKGROUND
• gFOBT is about 30% sensitive and can go up to 90-92% with
serial sampling of 3.
• Normal person sheds about 0.5-1.5 ml of blood into stool over
24 hour period. gFOBT can detect as small as 2 ml to 10 ml of
blood in the stool per 24hrs .
• A good sample for gFOBT is when the patient is 72 hours off
medications or foods that can give false positive results such as:
NSAIDs and Aspirin, vitamin C, red meat, cantapoupe and other
melons, grapefruit, turnips, broccoli, figs, radhish, horseradish,
cauliflower, cabbage, cucumber, carrot, potato, pumpkin,
zucchini, parsley.
AIM
• To evalulate whether or not FOBT was ordered
appropriately or not
• To evaluate cost-effectiveness of FOBT
METHODS
•
Chart review of 10 patients who have been admitted in April with FOBT performed.
•
Acceptable indications for ordering FOBT AT ADMISSION (the FOBT is Hemmocult) on 1
study:
• Symptoms of acute or chronic GI bleeding (e.g., hematemesis, melena)
• Physical signs of anemia (e.g., pallor)
• Anemia on admission complete blood count
• Report of weight loss of at least 4.5 kg within 6 mo
• Symptoms of enteric illness (fever, diarrhea)
• Change in bowel habits or tenesmus
• History of prior GI malignancy
• History of colonic abnormalities (e.g., diverticula, arteriovenous malformation)
• Other indications: anticoagulation therapy, coagulopathy, history of benign GI lesions
1Gomez
JA and Diehl AK. Admission stool guaiac test : Use and Impact on patient
management. The American Journal of Medicine 1992; 92: 603-06.
PATIENTS
• 10 patients age from 26 to 90
• 8 females and 2 males
• All were admitted at UCIMC in April 2013
• Primary services include IM (4), family medicine, OB/GYN,
General/Trauma surgery, Neurosurgery, CCU
RESULTS
• All 10/10 cases are deemed inappropriate. All are from Internal
Medicine (3/4). 2 were ordered at the time of admission.
• 10 cases: the test was ordered without mentioned in the
notes. They were ordered during hospitalization. No follow
ups were done regardless of results of the test.
• 1/10 was ordered at admission with a history of anemia with
lower than usual Hgb without recent scopes and rectal exam
was negative for blood.
• 1/10 was ordered at admission on a patient with
hematemesis and melena.
RESULTS
• 1/10 was done during hospitalization per renal
recommendation as work up for elevated BUN which renal
consult did not think it was due to kidney injury.
• 5/1/10 cases: the test was done because of acute Hgb drop
from 11.4 to 10.2 over 24 hours. The patient has a history of
anemia.
• 1/10 cases: the test was done because of loose stool without
blood in the stool reported. Test was positive but nothing
was followed (not mentioned in the notes or consulting GI
etc.)
COST CONCIOUSNESS
• The cost of the test to performed is almost $20.00. The patient
Is billed almost $60.00.
• Imagine how common FOBT is ordered as a reflex for acute
Hgb drop, diarrhea, etc. 100 unnecessary tests could easily cost
the patients $6000.00
REMINDER
• FOBT is recommended for colorectal caner screening.
• Because of low sensitivity and specificity of the test, the results
are not benefiting in inpatient setting (1 single testing 30%
sensitivity with each test for a combination of 3 test, the
sensitivity can go up to 92% in a condition of being compliant for
3 days of restricted foods and medications).
• The upcoming FIT test is even more specifically designed for
colorectal cancer screening as it only picks up lower GI bleed.
Therefore, ordering in the inpatient setting is even more
inappropriate.
CONCLUSION
• Be very mindful of ordering FOBT in the inpatient hospital
setting. Very soon, there will be only FIT test available!
• What is the point of ordering the test without follow-up? There
were studies in the past that FOBT was done and the rate of
follow up on this test is very low (~30%).
THANK YOU