A Test Is Used to Diagnose Dementia in a Population

question 36

Multiple Choice

A test is used to diagnose dementia in a population of 1,000 women age ≥75.  The test has a sensitivity of 80% and a specificity of 90%.  The test is then used as a diagnostic tool in 2 other populations of women of the same age: population 1 has a prevalence of dementia of 15%, and population 2 has a prevalence of dementia of 30%.  Which of the following best describes how the negative predictive values (NPV) and the positive predictive values (PPV) from populations 1 and 2 relate to each other?

• A)NPV and PPV do not change as prevalence changes
• B)NPV in population 1 < NPV population 2; PPV in population 1 < PPV population 2
• C)NPV in population 1 < NPV population 2; PPV in population 1 > PPV population 2
• D)NPV in population 1 > NPV population 2; PPV in population 1 < PPV population 2
• E)NPV in population 1 > NPV population 2; PPV in population 1 > PPV population 2

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Definitions:

Authority

The authority or capability to make decisions, issue commands, and ensure compliance.

Chaos

A state of extreme confusion and disorder, where there is little to no predictability or control.

Strategic Leaders

Individuals who have the responsibility of guiding an organization towards achieving its long-term goals and objectives.

Visionary Abilities

The capacity to foresee future trends, challenges, and opportunities, enabling leaders to steer organizations effectively towards long-term goals.