Evaluation of health-related quality of life in low-income patients with COPD receiving long-term oxygen therapy

Study objective: To assess health-related quality of life (HRQL) in a low-income population of patients with hypoxemia and COPD receiving long-term oxygen therapy (LTOT). Design: Cross-sectional study. Setting: Large, tertiary care, university teaching hospital. Patients or participants: Thirty-six patients with COPD requiring LTOT (mean age, 63.5 years; mean FEV1, 32.1 % of predicted; Pao(2), 50.2 mm Hg) and 33 control subjects with COPD hut no severe hypoxemia (mean age, 63.1 years; FEV1, 35.7%; Pao(2), 66.5 mm Hg). Interventions: Patients underwent pulmonary function testing to assess physiologic function and the degree of respiratory impairment. A baseline dyspnea index (BDI) was used to determine levels of dyspnea, and a 6-min walk test was performed to evaluate physical performance and exercise capacity. The St. George Respiratory Questionnaire (SGRQ) and the Medical Outcomes Study Short-Form 36-item questionnaire (SF-36) were used to assess health status and HRQL. Measurements and results: The scores on the SGRQ and SF-36 indicated severe impairment. Patients receiving LTOT showed a trend toward worse scores on most dimensions of the SGRQ and SF-36, but differences between groups were only statistically significant for the physical functioning and social functioning dimensions of the S F-36. Dyspnea, as measured by the BDI, significantly correlated with all questionnaire domains except the SF-36 pain index. Conclusions: The HRQL of these low-income patients with COPD was markedly impaired, with more pronounced impairment in those receiving LTOT. The severity of dyspnea was a significant predictor of various components of quality of life in these patients.