Functional status and quality of life in chronic obstructive pulmonary disease

Exertional dyspnea often causes patients with chronic obstructive pulmonary disease (COPD) to unconsciously reduce their activities of daily living (ADLs) to reduce the intensity of their distress. The reduction in ADLs leads to deconditioning which, in turn, further increases dyspnea. Both dyspnea and fatigue are important factors affecting health-related quality of life (HRQOL). The functional status of patients relates to how well they perform ADLs. Activities, however, may not be severely limited until the disease becomes advanced. The elimination of an ADL depends on the necessity or desirability of that activity and the intensity of the associated symptoms. HRQOL is measured using symptoms, functional status, and a rating of their impact on the individual. The Pulmonary Functional Status Scale (PFSS) and the Pulmonary Functional Status and Dyspnea Questionnaire (PFSDQ) are 2 COPD-specific functional status questionnaires. Pedometers or accelerometers can quantify the levels of activity of patients with COPD. HRQOL is measured with validated multidimensional questionnaires that cover symptoms, physical, psychological, and social domains. Ideally, these instruments are discriminative (i.e., separate degrees of impairment) and evaluative (i.e., detect small changes after therapy). HRQOL questionnaires may be generic (e.g., Medical Outcomes Study Short Form-36 [SF-36]) and can measure favorable changes after intervention, such as pulmonary rehabilitation, or they can be disease specific with disease-related domains, e.g., Chronic Respiratory Disease Questionnaire (CRQ) with domains of dyspnea, fatigue, emotion, and mastery; and St. George's Respiratory Questionnaire (SGRQ) with domains of symptoms, activity, and psychosocial impact. A case is presented that depicts how these tools may be used to evaluate improvement with intervention in a patient with COPD.