What type of study is used to verify the accuracy of a new analytical method against a reference method?

• A. Correlation study
• B. Randomized controlled trial
• C. Prospective cohort study
• D. Case-control study

Answer: (A)

To check a new analytical method against a reference method, you look at how closely their results track each other across samples. A correlation study is used because it quantifies the strength and direction of the linear relationship between the two sets of measurements. A high correlation indicates the new method responds in a similar way to the reference method across the range of values, which is a key aspect of demonstrating accuracy. In practice, you’d also examine agreement and potential bias with analyses like Bland-Altman or regression, but the essential step to show that the new method corresponds to the reference is assessing their correlation. The other study designs—randomized trials, prospective cohorts, and case-control studies—are intended to study outcomes or associations in populations, not to validate analytical measurement accuracy.