In a 2x2 contingency table, which statement defines a true positive?

In a 2x2 contingency table, which statement defines a true positive?

• A. Condition present and test positive.
• B. Condition absent and test positive.
• C. Condition present and test negative.
• D. Condition absent and test negative.

Answer: (A)

A true positive occurs when the person actually has the condition and the test result is positive. In a 2x2 contingency table, this is the scenario where the condition is present and the test indicates positive. This combination shows the test correctly detecting those with the condition. If the condition is absent but the test is positive, that’s a false positive. If the condition is present but the test is negative, that’s a false negative. If the condition is absent and the test is negative, that’s a true negative.

A true positive occurs when the person actually has the condition and the test result is positive. In a 2x2 contingency table, this is the scenario where the condition is present and the test indicates positive. This combination shows the test correctly detecting those with the condition.

If the condition is absent but the test is positive, that’s a false positive. If the condition is present but the test is negative, that’s a false negative. If the condition is absent and the test is negative, that’s a true negative.