simple biostat - kallastro

[ArchivalUser]

You are evaluating an 8-year-old child with abdominal pain for possible appendicitis. Laboratory testing shows a white blood cell (WBC) count of 7.9 x 109/L. You are wondering whether to pursue the diagnosis further, when your attending physician remarks that the absence of leukocytosis has a negative predictive value (NPV) of 62% for appendicitis. Based on this information, what would you conclude?


A. The probability of not having appendicitis is 62% in the absence of leukocytosis
B. Approximately 62% of patients without appendicitis will not have leukocytosis
C. The positive predictive value for leukocytosis is 38%
D. You need to review your evidence-based medicine

[ArchivalUser]

NPP- Tell you that, what is the Chance of a Test (Specificity- to Rules out Disease) that came back negative is Truly Negative

So I Say its B

[ArchivalUser]

A.

The NPV is the probability of a true negative (absence of appendicitis) given a negative test result (no leukocytosis). The probability of a negative test result given the absence of disease (option B) describes the specificity of the test, whereas 38% is the false-negative rate (1 “ NPV). The positive predictive value cannot be derived from the information given.

[ArchivalUser]

agree its B

[ArchivalUser]

sorry got it mixed up. Nice Review!