RESUMO
The quality of life in patients with chronic obstructive pulmonary disease [COPD] is associated with poor pulmonary function, respiratory symptoms, incapacity to perform daily activities, as well as mental and cognitive disorders. Although there exists some evidence regarding the effect of socioeconomic status on the quality of life in the general population and those with chronic diseases, research is scarce on this issue in COPD patients. This study aimed to investigate the association between income and quality of life in COPD patients. In a case-control study, 131 subjects were selected through systematic sampling from all COPD patients admitted to the pulmonology Clinic of the Baqiyatallah Hospital during the year 2006. Subjects were then divided into three groups based on their household monthly income as follows: group I [n=52], income < 2,000,000 Rials; group II [n=62], income between 2,000,000 and 3,000,000 Rials; and group III [n=17], income > 3,000,000 Rials. The groups were matched with regard to gender, age, educational background, marital status, comorbidity burden, and insurance coverage. Spirometric measures and quality of life [SF-36] were compared between the groups. The overall quality of life and physical health subscale were significantly different between the groups [p < 0.05]. Other parameters of SF-36 including physical functioning, role limitation due to physical problems, bodily pain, social functioning, general mental health, role limitation due to emotional problems, vitality, and mental health exhibited no significant difference between the groups [p > 0.05]. Quality of life and physical function of COPD patients are significantly correlated with their socioeconomic status. Future prospective studies are needed to find potential causative associations between the level of income and life quality in these patients