Functional assessment in rheumatic diseases

Standardized assessments of general physical function (e.g. walking unaided) and the ability to perform tasks of daily living are widely used in rheumatology, both in clinical practice to assess disease severity and progression, and in clinical research to evaluate the effectiveness of treatment. Some measure of physical function is now included in the core data set recommended for inclusion in all clinical trials in rheumatology. Several different methods and tools are available for measuring function and most have been extensively validated for use in research. These vary from directly observed performance of activities such as walking, sitting and standing, to patient-completed questionnaires of the perceived difficulty they experience in performing daily living activities or undertaking roles. This article reviews the different approaches used, together with their advantages and disadvantages.