Chem 3 Flashcards
(9 cards)
What are the three levels of variation and error in test characteristics?
Pre-analytical, Analytical, Post-analytical
These levels must be considered even if an analytic method is free from all sources of variation.
What are the key factors considered in interpreting test results?
Sensitivity, Specificity, Negative predictive value (NPV), Positive predictive value (PPV), Diagnostic efficiency, Diagnostic Sensitivity
These factors are critical for understanding the accuracy and reliability of test results.
What does diagnostic sensitivity indicate?
How truly patients with MI would produce a positive test result
MI refers to myocardial infarction.
What does diagnostic specificity indicate?
The frequency of a negative result in patients who do not have an infarction
High specificity reduces false positives.
What is the positive predictive value (PPV)?
The probability that the disease in question is actually present if the test result is positive
PPV is crucial for understanding the reliability of a positive test result.
What is the negative predictive value (NPV)?
The probability that the disease in question is actually absent if the test result is negative
NPV helps in assessing the reliability of a negative test result.
Fill in the blank: The formula for positive predictive value is the number of patients with _______ divided by the total number of patients with a positive test result.
True-positive (TP)
This formula helps calculate the likelihood of disease presence based on test results.
Fill in the blank: The formula for negative predictive value is the number of patients with _______ divided by the total number of patients with a negative test result.
True-negative (TN)
This formula is essential for determining the likelihood of disease absence based on test results.
What is diagnostic efficiency?
The overall proportion of correct (both positive and negative) test results for all the subjects tested
It reflects the accuracy of the diagnostic test in the tested population.
