Ordering Lab Test II Flashcards
Inexperienced clinicians do what..?
Very complete and thorough - but have a shotgun approach to laboratory testing
Experience clinicians do what?
Focused exam/history
Highly focused tests on one or a few number of diagnoses
How is a focused approach made possible?
Cognitive shortcuts - known as heuristics
Representativeness heuristic
Does pts’ presentation match that of other pts with a particular syndrome?
Relies on the clinician having experience or at least knowledge of a syndrome
Clinician needs to be congnizant of the PREVALENCE of various syndromes that are considered
Clinician should recognize that his/her experience with the syndrome, if limited ,could limit reliability of the match
Availability heuristic?
How quickly or readily does a syndrome come to mind when considering the pts presentation?
The clinician may have seen several exs of a syndrome that matches the presentation but does not represent the most common diagnosis for the presentation (Txtbook standards)
Recollections of disastrous misdiagnoses may sway the clinicians perception
Anchoring heuristic
A particular finding, such as a radiographic result, may “anchor” the assessment of disease probability and influence the further refinement of a diagnostic approach
This can be flawed if disease prevalence, given the pts circumstances is not taken into account
Latching on to an anchor too early, and not fully considering additional information, is one of the most common errors when using heuristics
Premature closure
accepting a diagnosis before verification
Confirmation bias
The tendency to pay attention to confirming evidence and place less trust on refuting evidence for your diagnosis
Context error
The context in which evidence is presented causes the interpretation of the evidence to be distorted
Diagnostic stewardship?
Right test for the right pt, at the right time
Lab testing that is not justified can lead to diagnostic and/or therapeutic misadventures
Unnecessary diagnostic testing drives up the cost of medical care w/o benefit to pts
There is a consensus that overutilization of lab testing is rampant, especially where?
Inpatient settings
“Confirming” an established diagnosis with lab testing” may be unnecessary
“Shotgun” testing may be excessive, as compared to algorithmic approach
Tests that provide essentially the same information may be ordered simultaneously
Some have argued that there is evidence of underutilization of lab testing where?
Outpt setting
Shotgun testing?
Do one test then the other instead of both at the same time because the next one might be unnecessary depending on what the first results said
What are some influences on physician utilization of resources?
Defensive medicine
Availability of resources (more specialists, more hospital bed)
Economic factors (fee for service model, fixed salaries/capitation favor less)
Lab stewardship (lap utilization) efforts - hospital commutes define best practices; focus on reducing hospital costs but also pt charges
Who does the lab bill?
Lab pills pt insurance, not physician practices
Physicians must provide a justification, a ICD-10 code for lab test orders
Some lab tests, especially expensive genetic tests require pre-authorization; insurance companies can refuse these if they do not alter the outcome for pts
Custom panels for individual physicians are NOT allowed - only BMP and CMP are used - medicare approved
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Physicians may not receive inducements from labs, to utilize that lab for diagnostic services; that is illegal
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No one pays “retail” for lab tests….
Providers are restrained from balance-billing the pts
Self - pay are given discount provided by provider
Justification for screening tests?
Early detection where it can be cured or when tx can be done will reduce morbidity/ mortality and cost to society
Methods of measuring benefits of screening? (4)
1) average increase in life expectancy
2) cost per year of life saved
3) cost per year of morbidity avoided
4) number of individuals screened in order to change the outcome in one pt
Tumor marker exs?
PSA
Beta-hCG - choriocarinoma
CEA - colon cancer
CA 27.29 - breast cancer
CA125 - ovarian cancer
What is the government’s position on screening tests?
Agency for Heatlhcare Research and Quality for U.S. Preventative Services Task Force recommendations
PSA screening has shown to have no, or little impact on reducing chance of men dying of prostate cancer and the treatment can produce impotence, incontinence, etc….
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Preanalytical error
Most common errors are:
Mislabeled or unlabeled specimens
Order error
Incorrect specimen type, handling
Incorrect patient preparation (doing it too soon after other procedure in case of PSA)
Analytical error
Instrument/reagent flow not detected by quality control procedures
Calibration error not detected by quality control procedures
Wrong specimen/wrong test
Post analytical error
Report not channeled to the correct care provider in a timely fashion
Result is misinterpreted by the clinician
When a lab result does not match your clinical assessment….
Question the result!
Call the lab to discuss
- mislabeled aliquot tube can be investigated
- specimen can often be re-assayed
- new specimen can often be obtained and tested
