DO Diagnostic Reasoning and Evidence-Based Medicine 3

Question 1

The likelihood ratio positive (LR+) for a diagnostic test is calculated as:

Accepted Answer

Sensitivity / (1 - Specificity)

Answer

(1 - Sensitivity) / Specificity

Answer

Sensitivity × Specificity

Answer

Positive predictive value / Negative predictive value

Question 2

When interpreting diagnostic tests, which situation should prompt concern about verification bias?

Accepted Answer

Disease status confirmed only in patients with positive screening tests

Answer

All study participants receive the gold standard test regardless of screening result

Answer

Disease prevalence is evenly distributed across study groups

Answer

Random allocation to diagnostic pathways is used

Question 3

In clinical practice, a decision threshold (test threshold) represents the probability at which:

Accepted Answer

Testing is warranted based on pre-test probability and test risk/benefit

Answer

Treatment should begin regardless of test results

Answer

All patients receive the same diagnostic workup

Answer

Further testing always occurs regardless of current probability

Question 4

Which statistical test is most appropriate for comparing means of a continuous variable between two independent groups with normally distributed data?

Accepted Answer

Independent samples t-test

Answer

Chi-square test

Answer

Mann-Whitney U test

Answer

ANOVA

Question 5

Premature closure in diagnostic reasoning is best described as:

Accepted Answer

Accepting a diagnosis before all relevant information has been gathered

Answer

Performing too many diagnostic tests

Answer

Failing to consider the most common diagnoses first

Answer

Delaying diagnosis due to excessive testing

Question 6

Forest plots in meta-analyses display each study's result as a square with a horizontal line. What does the horizontal line represent?

Accepted Answer

The 95% confidence interval for that study's effect estimate

Answer

The sample size of the study

Answer

The p-value of the study result

Answer

The weight assigned to the study in the pooled analysis