LabDx

9/20/99

 

Testing Strategy

• Extra costs are incurred here above the office visit
• Would like to start treatment from a DDx for low risk groups
• This keeps you competitive in the market
• Diagnostic imaging
• Plain films
• CT
• MRI
• Ultrasound
• Laboratory
• Physiological

 

Selection Criteria

• Sensitivity—test will be positive when the pt has the disorder
• Would like 100%
• Rarely do we find a test that we can afford that is 100%
• Have to weigh the amount of certainty you want to the cost (esp. in geriatric population)
• Instead may wait and monitor the pt for awhile and see if respond w/o the test
• False negatives are when a test doesn't detect the problem
• Specificity—test is negative when the pt doesn't have the problem
• Negative tests and Negative labs to not make a normal pt
• Predictive value—you want a solid, quality test done to get the most accurate answer
• Positive
• Negative
• Test quality
• Will alter sensitivity and specificity depending upon the population that you are evaluating
• Determines test quality factors in the prevalence of pathology

 

Sensitivity

• Fracture of the C-spine
• High sensitivity
• CT
• Bone Scan--$700, 95-97% sensitive
• Cancer, spondylolysis, occult fractures

 

Specificity

• Think that you have a fracture
• Do a bone scan
• Has a high specificity for fracture, in the high 90%

 

EPT (early pregnancy test)

• 93-94% accuracy
• Higher sensitivity would be an ultrasound that cost several hundred dollars
• Specificity is about 95%

 

Treatment

• Mirrors Dx
• Functional, spiritual, ??
• You are not trying to get rid of pain, the pain will go away as the function and etc improves
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