Socioeconomic status and health-related quality of life of patients with chronic obstructive pulmonary disease.

BACKGROUND: Socioeconomic status (SES) is an important determinant of health and premature death. However, the impact of poor SES on the health status of patients with chronic obstructive pulmonary disease (COPD) has not been well determined.
OBJECTIVE: It was our aim to assess the impact of SES on the quality of life in COPD patients.
METHODS: This was a cross-sectional, observational, multicenter study. A total of 4,574 patients completed the EuroQol 5-dimension questionnaire (EQ-5D) and the Airways Questionnaire 20 (AQ20). SES was based on the subject's occupation and educational level. Occupational categories were based on the major group classification of the International Standard Classification of Occupations.
RESULTS: The mean age of the population was 67.1 years and the mean forced expiratory volume was 43.4%. There was a gradient of impairment in health-related quality of life (HRQoL) according to the educational level, with significantly worse scores for the EQ-5D and the AQ20 for medium and low educational levels compared with high education (p < 0.001). Similarly, HRQoL was also significantly impaired in more unskilled workers, with a gradient of the AQ20 from 8.6 units (SD 4.8) in class I to 10.1 units (4.6) in class V (p < 0.001) and from 0.75 units in class I to 0.63 units in class V for the EQ-5D index, as well as from 62.9 units in class I to 55.6 units in class V for the EQ-5D visual analogue scale (p < 0.001 for all comparisons). These differences remained significant after controlling for covariates.
CONCLUSIONS: Patients with a lower educational level and belonging to the unskilled professional groups had a poorer HRQoL. This is evident even in a country where access to health care services is universal and free.