Does long-term oxygen therapy affect quality of life in patients with chronic obstructive pulmonary disease and severe hypoxaemia?

Abstract

Long-term oxygen therapy (LTOT) improves survival in patients with hypoxaemic chronic obstructive pulmonary disease (COPD), but previous studies using general health measures have shown no effect on quality of life (QoL). In this study, the effect of LTOT on QoL was assessed using a disease-specific health measure, the St George's Respiratory Questionnaire (SGRQ). Twenty three hypoxaemic COPD patients (15 females and 8 males) were studied before and after starting LTOT: median age 71 (range 47-82) yrs, mean (SD) forced expiratory volume in one second (FEV1) 0.75 (0.22) L, arterial oxygen tension (Pa,O2) 6.95 (0.75) kPa, arterial carbon dioxide tension (Pa,CO2) 6.52 (1.21) kPa. A control group comprised 18 COPD patients (6 females and 12 males) with less severe hypoxaemia: median age 72 (range 58-85) yrs, FEV1 0.94 (0.33) L, Pa,O2 8.17 (0.94) kPa, Pa,CO2 6.02 (0.75) kPa. QoL was measured at baseline, 2 weeks, 3 and 6 months. The LTOT group had higher SGRQ total scores than controls (p<0.05) at all visits, implying lower QoL. Repeated measures analysis of variance showed no effect of LTOT on QoL over 6 months (F=0.43, p=0.79). In this study we detected no change in quality of life using a disease-specific health measure in patients with severe chronic obstructive pulmonary disease using an oxygen concentrator to provide long-term oxygen therapy.