The challenges inherent with anchor-based approaches to the interpretation of important change in clinical outcome assessments

PurposeAnchor-based methods are group-level approaches used to derive clinical outcome assessment (COA) interpretation thresholds of meaningful within-patient change over time for understanding impacts of disease and treatment. The methods explore the associations between change in the targeted concept of the COA measure and the concept measured by the external anchor(s), typically a global rating, chosen as easier to interpret than the COA …