Biochemistry - Biochemistry Tests Flashcards
What is clinical biochemistry?
The investigations and tests organised to understand what the problem is and help rule out specific diagnoses considered. Slide 3
What are clinical biochemistry tests used for?
Diagnosis, guiding treatment, prognosis and screening. Slide 4
What is a true positive result?
Where the test is abnormal in a person with the disease. Slide 13
What is a false positive result?
Where there is an abnormal test result but the disease is absent
What is a false positive result?
Where there is an abnormal test result but the disease is absent. Slide 13
What is the sensitivity of a test and how is it calculated?
How well it detects a disease.
Calculated by TP/[TP+FN]. Slide 17
What is the specificity of a test and how is it calculated?
It is how good the test is to detect the absence of disease.
Calculated by TN/[TN+FP]. Slide 18
What is a positive predictive value and how is it calculated?
The percentage of people with a positive test and the disease.
Calculated by TP/[TP+FP]. Slide 19
What is a negative predictive value and how is it calculated?
The percentage of people with a negative test and don’t have the disease.
Calculated by TN/[TN+FN]. Slide 20
What is prevalence and how is it calculated?
The percentage of people tested who have the disease.
Calculated by TP+FN/[TP+FN+TN+FP]. Slide 21
What happens to PPV an NPV when prevalence falls?
PPV falls and NPV rises. Slide 24
