Scientific and rigorous study design could improve the reliability of results of the comparative diagnostic test accuracy studies. The design procedures of a comparative diagnostic test accuracy study included: constructing the clinical questions, identifying the appropriate gold standard, selecting the representative patient sample, calculating the sample size, blindly interpreting and comparing the results of diagnostic tests, and setting up the cut-off value. This paper introduced 5 categories of the designs of comparative diagnostic test accuracy studies: fully paired, partially paired with a random subset, partially paired with a nonrandom subset, unpaired randomized, and unpaired nonrandomized design.
By comparing the diagnostic accuracy of two or more tests in the same study, the one with the higher diagnostic accuracy can be screened. Therefore, it is extremely important to conduct the comparative diagnostic test accuracy study. This paper introduced the concept of the comparative diagnostic test accuracy study, compared it with single diagnostic test accuracy study, and described its role, study design, statistical analysis, current status, and challenges.