RESUMO
BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung disease and is usually associated with a poor prognosis. IPF patients have a significant impairment in health-related quality of life (HRQL), both in terms of physical and psychological functioning. A substantial number of dyspnea scales are available to clinicians for clinical and research use. The objective of the present study was to investigate how some commonly used dyspnea scales correlate with measurements of HRQL in IPF patients. MATERIAL/METHODS: A group of 30 patients with IPF who attended a specialized outpatient respiratory clinic were interviewed during a stable period of the disease. HRQL was assessed by the SF-36 questionnaire. Dyspnea was measured by the baseline dyspnea index (BDI), Modified Medical Research Council Scale (MRC), Oxygen Cost Diagram (OCD), clinical element of the Clinical, Roentgenographic and Physiologic score (CRP), and a new dyspnea scale (NS) based on estimates of required oxygen consumption for usual activities. RESULTS: Patients showed impairments in all HRQL domains except the Pain Index. All dyspnea scales showed significant correlations with both physical and mental HRQL domains. The highest Spearman's coefficients between dyspnea ratings and SF-36 components were obtained using the BDI. CONCLUSIONS: Dyspnea ratings correlate with HRQL measurements in IPF patients. Dyspnea scales can be used as a measure of HRQL in special circumstances.