Factors determining outcome in elderly patients with severe COPD on long-term domiciliary oxygen therapy

The objective of the present study was to identify factors that determine outcome in elderly patients receiving long term domiciliary oxygen therapy (LTOT) for chronic obstructive pulmonary disease (COPD). One hundred fifty-seven COPD patients (121 male, 36 female) receiving LTOT were followed-up from 1983 to 1994. Univariate and multivariate analysis by Cox's proportional hazards ratio model and Kaplan-Meier survival estimates were used to quantify the relationship among a total of 34 baseline variables and overall mortality. By December 31, 1995, 96 patients (61.2%) had died and 13 (8.3%) were unavailable for follow up. Mean age of the patients was 79.2 yrs and mean duration of LTOT was 2.81 yrs. The mean FEV1 was 0.80 L and mean FEV1/FVC was 48%. The overall survival was poor and 5-yr survival was 21.6% (median survival: 3.01 yrs). Among the variables tested by univariate analysis, factors associated with poor outcome were as follows: %IBW < or = 85 (HR = 2.15, p < 0.001), serum albumin (g/dl) < or = 3.5 (1.81, p < 0.01), hemoglobin (g/dl) < or = 11.0 (1.86, p < 0.01), FEV1/FVC > 50% (0.63, p < 0.05), and high dyspnea ranking (grade 4 or 5) (1.74, p < 0.05). The coexistence of bronchiectasis (3.96, p < 0.01) and malignancy (1.85, p < 0.01) also contributed to poor outcome. Multivariate analysis showed that independent prognostic factors influencing outcome included: nutritional status (%IBW) (HR = 2.08, p < 0.01), dyspnea ranking (2.04, p < 0.01), coexistence of malignancy (2.02, p < 0.01), and FEV1/FVC (0.52, p < 0.01). We conclude that the outcome in elderly COPD patients receiving LTOT is poor, and that outcome is independently influenced by four major factors: malnutrition, severity of dyspnea, coexistence of malignancy, and airflow obstruction.