A 34-year-old man is taken to the hospital complaining of severe chest discomfort. In the emergency department, an ECG is acquired, which shows ST segment elevation in leads II, III, and aVF. A blood sample is collected from the patient, and plasma homocysteine levels are measured using a novel assay. The test is done three times with his blood sample, yielding 11.8 mol/L, 9.2 mol/L, and 13.7 mol/L findings (laboratory reference range: 4-14). Based on the findings of the new test, which of the following metrics is most likely to be low?

Question

Quizplus · Accepted Answer

Eductional Objective: A measurement tool should be precise and accurate to be useful in the clinical setting. Precision and accuracy are defined as follows:
Precision (reliability) is the ability of a test to reproduce identical or similar results with repeated measurements (bottom half of figure).
Accuracy (validity) is the ability of a test to measure what it is supposed to measure. For a new test to be accurate, its results should be equivalent to the results obtained with a "gold standard" (eg, best conventional test available) on the same individual (right half of figure).
A precise test gives similar or very close results on repeat measurements. In this example, repeat measurements of the same sample yielded different results; therefore, the new test has low precision.

A 34-Year-Old Man Is Taken to the Hospital Complaining of Severe