The American Diabetes Association (ADA) recently lowered the cut off value for fasting glucose used in diagnosing diabetes mellitus from 140 mg/dL to 126 mg/dL. This reference interval change would be expected to produce which of the following alterations?
The negative predictive value of a test (PV-) refers to the percent chance that a normal test result is a true negative (TN; a healthy person with a normal test result) rather than a false negative (FN; a diseased person with a normal test result). It is expressed by the following formula: PV- = TN/(TN + FN) Similarly, the positive predictive value of a test (PV+) reflects the probability that an abnormal test result represents a true positive (TP) rather than a FP (a TP is an abnormal test result in an individual with disease, while a FP is an abnormal test result in a healthy person). PV+ is calculated using the following formula :PV+ = TP/(TP + FP)
Decrease the test's sensitivity
Increase the test's false negative rate
Increase the test's negative predictive value
Increase the test's positive predictive value