Health-related quality of life, lung function and dyspnea rating in COPD patients.

BACKGROUND AND AIM COPD is a progressive and irreversible disease, thus assessing the impact of the disease on health-related quality of life (HRQOL) is important in the management of COPD. The aim of this study was to examine the relationship between HRQOL, lung function and dyspnea rating in patients with stable COPD. METHODS One hundred COPD patients (mean age = 64.76 +/- 11.43 years) were recruited for this cross-sectional study. Lung function test was measured using a FlowScreen portable spirometry. Dyspnea rating was measured using the baseline dyspnea index (BDI). HRQOL was assessed using the SF-36v2 which summarized two components; physical health component summary (PHCS) and mental health component summary (MHCS). THE RESULTS The mean value of lung function (Forced expiratory volume in 1 second, FEV1% predicted) was 58.19 +/- 30.24 and dyspnea rating was 6.85 +/- 2.68. The lung function was significantly correlated with MHCS (r=.294, p < 0.05) but not with the PHCS (p > 0.05). The dyspnea rating was significantly correlated with both PHCS (r=.730, p < 0.05) and MHCS (r = .324, p < 0.05). Regression analysis indicated that dyspnea rating emerged as the most significant predictor for PHCS and MHCS accounting for 54% and 12% of the variances respectively. CONCLUSIONS The findings show that dyspnea rating is an important factor in predicting HRQOL of patients with COPD. This indicates that dyspnea rating influences HRQOL to a greater extent than the physiological measurement of lung function. Therefore, focusing on such predictors at an early stage may provide meaningful benefits in the management of COPD.