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; Pao2, 50.2 mm Hg) and 33 control subjects with COPD but no severe hypoxemia (mean age, 63.1 years; FEV1, 35.7%; Pao2, 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 SF-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.