OBJECTIVE: The value of a new diagnostic test is usually established by analyzing its accuracy in relation to a reference standard. Here we describe a potentially better model of diagnostic research, namely, a diagnostic randomized clinical trial (D-RCT), and discuss its pros and cons using management of critical limb ischemia as an example. STUDY DESIGN AND SETTING:Patients clinically suspected of critical limb ischemia are randomized either for the conventional management strategy (treating physician determines the diagnostic and therapeutic strategy on clinical judgment and ankle pressure) or new strategy (transcutaneous oxygen and toe pressure determine the diagnostic and therapeutic strategy). The effect of the diagnostic work-up on the diagnostic and therapeutic process and clinical outcome will be evaluated. RESULTS: A D-RCT is suited when a true reference standard is lacking. It is the best available research method to control for confounding and bias, and it also incorporates the total effect (interpretation and side effects) on clinical outcome. The D-RCT has some disadvantages, however, as to the power and size of the trial and the influence of treatment on the outcome parameter. CONCLUSIONS: A D-RCT can provide valuable information as to the evaluation of diagnostic tests.
RCT Entities:
OBJECTIVE: The value of a new diagnostic test is usually established by analyzing its accuracy in relation to a reference standard. Here we describe a potentially better model of diagnostic research, namely, a diagnostic randomized clinical trial (D-RCT), and discuss its pros and cons using management of critical limb ischemia as an example. STUDY DESIGN AND SETTING:Patients clinically suspected of critical limb ischemia are randomized either for the conventional management strategy (treating physician determines the diagnostic and therapeutic strategy on clinical judgment and ankle pressure) or new strategy (transcutaneous oxygen and toe pressure determine the diagnostic and therapeutic strategy). The effect of the diagnostic work-up on the diagnostic and therapeutic process and clinical outcome will be evaluated. RESULTS: A D-RCT is suited when a true reference standard is lacking. It is the best available research method to control for confounding and bias, and it also incorporates the total effect (interpretation and side effects) on clinical outcome. The D-RCT has some disadvantages, however, as to the power and size of the trial and the influence of treatment on the outcome parameter. CONCLUSIONS: A D-RCT can provide valuable information as to the evaluation of diagnostic tests.