How many midstream urine tests are performed a year in the United
States? What percent of these midstream urine tests results have false
positive readings? You must be able to validate your answers. |
Request for Question Clarification by
richard-ga
on
21 Jan 2005 07:32 PST
Hello:
What particular tests do you have in mind? That is, false positives
for what compound or condition?
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Clarification of Question by
hendrie99-ga
on
22 Jan 2005 10:20 PST
Richard,
Thank you for the clarification question.
Im interested in knowing how many different conditions require a
mid-stream test and the estimated total of all mid-streams requested
during a year.
Im also trying to get a sense of how many times these samples have
false positives and require either a re-test (another mid-stream) or
different diagnostic test or physician just prescribes a medication.
Please let me know if you need further clarification. I hope this helps.
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Request for Question Clarification by
richard-ga
on
23 Jan 2005 05:02 PST
Hendrie99:
This is beyond what I'm able to provide. Perhaps another Researcher
will have better luck...
-R
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Request for Question Clarification by
crabcakes-ga
on
23 Jan 2005 11:29 PST
Hi hendrie,
I'm unable to give you numbers, but I can give you a few hints that
may help another researcher, or yourself, in finding the answer.
Midstream urine collections are usually only collected when a UTI
(Urinary tract infection) is suspected, and are usually called 'Clean
Catch' urines. By wasting the first part of a urine stream, vaginal
and urethral contamination is eliminated, or lowered to a point that
the it is insignificant. For routine screening for protein, glucose,
drug testing, specific gravity, pH, and ketones, a midstream sample is
not necessary.
Midstream urine collection is more costly. A sterile, often sealed
cup, is necessary, along with TWO antiseptic towelettes. A regular
urine sample is often collected in a Dixie cup in doctor's offices,
and a non-sterile cup(much cheaper)in hospitals and reference labs.
Some hospitals/clinics utilize a system called reflexive testing.
This can save money in populations where a clean catch urine is likely
to be necessary. A clean catch urine (midstream) is collected and
yested for a routine analysis. If particular parameters are positive
(red blood cells, white blood cells, bacteria, etc.) then the
performing lab would proceed with a microscopic portion and/or culture
and sensitivity. (Some labs do not even perform a microscopic analysis
if the dipstick portion is "normal".) Since laboratory personnel are
not allowed to perform tests without an order, this saves the ordering
physician time, by giving the lab permission to perfom additional
testing if the first test indicates something is positive.
So, good numbers would be difficult to analyze, because some clean
catch samples are unnecessary, and others are duplicate. More than
rarely, a patient does not follow the clean catch procedure, as
evidenced by unused towlettes left in the restroom, and
vaginal/urethral cells and bacteria contaminating the sample. Hence, a
second clean catch urine is requested(If the physician is concerend
enough). Vaginal and urethral contaminants can give false positive
results, both in the urinalysis and cultures.
Good luck,
crabcakes
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Request for Question Clarification by
pafalafa-ga
on
23 Jan 2005 11:51 PST
hendrie99-ga,
I've found some data on the market size for urine testing of all
types, but crabcakes-ga has raised an excellent point in the comment
above -- there is a significant difference between general urine
testing and "clean catch" tests using midstream testing.
Do you only want data on midstream testing...? If so, I'm not sure
this would be available, but we'll certainly look.
As for false positives, that sort of information is likely to be found
on a test-specific basis. That is, there is data on flase positives
for, e.g., urine tests for drugs, and separate data on urine tests for
bacterial infections. But there are not likely to be overall stats
for urine tests of all kinds.
Let us know in a bit more detail what you specifically need here, and
we'll see what we can do.
Thanks.
pafalafa-ga
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Clarification of Question by
hendrie99-ga
on
23 Jan 2005 12:54 PST
Thanks for the questions.
Im looking for numbers in regard to the midstream / clean catch only.
Im looking for false positives across all different types of specific
test ordered, i.e. UTI's, Kidney infections, Pregnancy, etc.
Your comment "So, good numbers would be difficult to analyze, because some clean
catch samples are unnecessary, and others are duplicate. More than
rarely, a patient does not follow the clean catch procedure, as
evidenced by unused towlettes left in the restroom, and
vaginal/urethral cells and bacteria contaminating the sample. Hence, a
second clean catch urine is requested(If the physician is concerend
enough). Vaginal and urethral contaminants can give false positive
results, both in the urinalysis and cultures."
That is exactly what Im trying to figure out.
I know this is difficult, that's why Im reaching out for extra research help.
I hope you can help.
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