Abstract
Background: COPD may influence different aspects of health-related quality of life (HRQL). Disease-specific HRQL instruments focus on symptoms and functional impairments while generic HRQL instruments cover a broader view on health.
Aims: To compare HRQL assessment by the generic EQ-5D and two disease-specific HRQL questionnaires (Saint George's Respiratory Questionnaire (SGRQ), COPD Assessment Test (CAT)) and to describe generic and COPD-specific HRQL in different COPD severity grades.
Methods: This study is a cross-sectional analysis of the baseline data from the German COPD cohort COSYCONET. Correlations between EQ-5D utility index, SGRQ total score, CAT score and GOLD grade or BODE index as clinical measures of COPD severity were examined by Spearman correlation coefficients. Mean HRQL scores were compared by linear regression models adjusting for age, sex, education.
Results: 2,288 subjects in COPD grade 1-4 (mean age 65 yrs, 61% males, 56% basic education, mean BODE 2.3) were included for analyses. Correlation between EQ-5D utility and SGRQ score (-0.56, p<0.001) and CAT score (-0.56, p<0.001) was moderate. Correlation between SGRQ and CAT scores was strong (0.78, p<0.001). BODE index and GOLD grade correlated best with SGRQ score (0.60, p<0.001; 0.39, p<0.001). Adjusted COPD-specific HRQL decreased steadily from grade 1-4 (SGRQ 28.7/39.0/48.4/58.3, p<0.001; CAT 14.3/17.0/19.2/21.8, p<0.001). Generic HRQL did not differ between grade 1 and 2 (0.85), but decreased to 0.82 (p=0.03) or 0.74 (p<0.001) in grade 3 or 4.
Conclusions: Generic and disease-specific HRQL instruments yield complementary information when aiming at a comprehensive picture of HRQL impairments in COPD.
- Copyright ©ERS 2015