Which statement about LR- is true?

Prepare for the Evidence-Based Practice (EBP) II Exam by engaging with our user-friendly quiz. Study with our collection of multiple-choice questions to improve your understanding and get ready to ace your exam!

Multiple Choice

Which statement about LR- is true?

Negative likelihood ratio shows how much a negative test result changes the odds of having the disease. The smaller the LR-, the more a negative result helps rule out disease. It’s calculated as (1 − sensitivity) divided by specificity, meaning it compares the chance of a negative result in diseased people to the chance of a negative result in non-diseased people. In practice, you multiply the pre-test odds by the LR- to get post-test odds after a negative result; a very small LR- greatly reduces the post-test probability of disease. That’s why lower LR- values indicate better ability to rule out disease. The other statements don’t fit: LR- is not Sn/Sp; it’s (1 − Sn)/Sp. It is used for interpreting negative results, not only positive ones. And a negative result with an LR- less than 1 reduces, rather than increases, the post-test probability of disease.

Negative likelihood ratio shows how much a negative test result changes the odds of having the disease. The smaller the LR-, the more a negative result helps rule out disease. It’s calculated as (1 − sensitivity) divided by specificity, meaning it compares the chance of a negative result in diseased people to the chance of a negative result in non-diseased people. In practice, you multiply the pre-test odds by the LR- to get post-test odds after a negative result; a very small LR- greatly reduces the post-test probability of disease. That’s why lower LR- values indicate better ability to rule out disease.

The other statements don’t fit: LR- is not Sn/Sp; it’s (1 − Sn)/Sp. It is used for interpreting negative results, not only positive ones. And a negative result with an LR- less than 1 reduces, rather than increases, the post-test probability of disease.

More practice questions