Factor Construct and Health Profile Which Define Quality of Life in Patients with Chronic Obstructive Pulmonary Disease

Abstract

Objectives. The purpose of this study was to assess the factor construct and health profile which define quality of life (QOL) in patients with chronic obstructive pulmonary disease (COPD) and to investigate the relationships between the main contributory factors of the health profile and overall QOL. Methods. The study group comprised 62 male patients with COPD aged ≥ 45 years and the control group was composed of 84 healthy men aged ≥ 45 years. Quality of life of patients and controls was assessed by the Taiwan version of the WHOQOL-BREF questionnaire. Subjects were asked to rank the importance of factors in each of four domains. The QOL factor construct was determined by exploratory factor analysis. The relationship between factors in the four domains of the questionnaire and the overall QOL was assessed by multiple regression analysis. Results. In the COPD group, the four-factor model accounted for 70.3% of the variance (9.1% for physical capacity, 42.4% for psychological well-being, 7.2% for social relationship, and 11.6% for environment). Ninety percent of individuals in the COPD group thought that physical capacity was the most important domain, compared with 57% in the control group. Multiple regression analysis showed that psychological well-being significantly affected overall quality of life among COPD patients and was highly correlated to the other three factors. Conclusions. The four-factor model derived from explanatory factor analysis is suitable to measure the quality of life in COPD patients and is comparable to the WHOQOL conceptual model. Psychological well-being was the dominant factor affecting COPD patients' overall quality of life. It is important therefore to not only evaluate patients' physical needs but also to assess psychological health to improve COPD patients' QOL. ( Mid Taiwan J Med 2004;9:103-12 )