Functional status measures for the COPD patient: A practical categorization

The objective of this study is to review available functional status measures (FSMs) validated for use in the chronic obstructive pulmonary disease (COPD) population and categorizing the measures by their commonalities to formulate a framework that supports clinicians in the selection and application of FSMs. A literature review identifying valid and reliable measures of functional status for people with COPD was undertaken. Measures were thematically analyzed and categorized to develop a framework for clinical application. A variety of measures of activity levels exist, with 35 included in this review. Thematic categorization identified five categories of measures: daily activity, impact, surrogate, performance-based, and disability-based measures. The vast variety of FSMs available for clinicians to apply with people who have COPD may be overwhelming, and selection must be thoughtfully based on the nature of the population being studied/evaluated, and aims of evaluation being conducted, not simply as a standard measure used at the institution. Psychometric testing is a critical feature to a strong instrument and issues of reliability, validity, and responsiveness need to be understood prior to measurement use. Contextual nature of measures such as language used and activities measured is also important. A categorical framework to support clinicians in the selection and application of FSMs has been presented in this article.