Developing a new reference standard: is validation necessary?

Overview

RATIONALE AND OBJECTIVES: A gold standard is often an imperfect diagnostic test, falling short of achieving 100% accuracy in clinical practice. Using an imperfect gold standard without fully comprehending its limitations and biases can lead to erroneous classification of patients with and without disease. This will ultimately affect treatment decisions and patient outcomes. Therefore, validation is essential before implementing a reference standard into practice. Performing a comprehensive validation process is discussed, along with its advantages and challenges. The different types of validation methods are reviewed. An example from our work in developing a new reference standard for vasospasm diagnosis in aneurysmal subarachnoid hemorrhage patients is provided. CONCLUSION: Employing a new reference standard may result in a definitional shift of the disease and classification scheme of patients; therefore, it is important to also assess the impact of a new reference standard on patient outcomes and its clinical effectiveness.