Health-related quality of life is associated with arterial P(O2) in chronic obstructive pulmonary disease.

Insensitive lung-specific questionnaires may explain the poor association between arterial P(O2) and reported health-related quality of life. Conceivably, modern lung specific or generic quality of life measures might show a better association with arterial P(O2). Fifty-nine outpatients (34 men) with chronic obstructive pulmonary disease (COPD) who fulfilled the following criteria were studied: age 18-67 years, FEV1 < or = 70%, < or = 15% reversibility after beta2-agonist inhalation, and no other disabling disorders. All completed the Respiratory Quality of Life Questionnaire (RQLQ) and Short Form 36 (SF-36), and were tested with spirometry and arterial blood gases. In accordance with available COPD staging systems, patients were divided into those with an FEV1 of < 50% and 50-70% of predicted. Patients' characteristics were, [mean (SD)]: age: 57.0 years (9.0); FEV1: 1.46 (0.6). Spearman's rank correlations between arterial P(O2) and dimensions of the RQLQ ranged from 0.25-0.52, and were greater than for the SF-36 (0.14-0.36) in patients with moderate to severe COPD. The association between arterial P(O2) and quality of life scores in moderately to severely affected COPD patients was moderate, but higher than previously reported. The associations were higher with a lung-specific questionnaire than with a general health measure, indicating a higher sensitivity of the lung-specific measure in this patient group.