Perceived quality of life in chronic obstructive pulmonary disease patients: a cross-sectional study in primary care on the role of illness perceptions

BACKGROUND: Previous research has shown that in Chronic Obstructive Pulmonary Disease (COPD) patients, it is important to consider not only physical functioning and complaints but also psychological factors, such as illness perceptions, to explain differences in Health-Related Quality of Life (HRQoL). The objective of this study is to analyse the extent to which the specific dimensions of illness perceptions according to the Common Sense Model (corrected for airflow limitation, dyspnoea and comorbidities) contribute to HRQoL. METHOD: In a cross-sectional study in primary care, 90 COPD patients completed questionnaires: The Brief Illness Perception Questionnaire, the Medical Research Council dyspnoea scale, the Clinical COPD Questionnaire (CCQ) and the Chronic Respiratory Questionnaire (CRQ). Analyses were performed with multiple linear regression. RESULTS: When corrected for confounders (airflow limitation, dyspnoea and comorbidities), identity (β = .42) and comprehensibility (β = -.16) were associated with HRQoL (CCQ). Identity, comprehensibility and dyspnoea explained 56% of the variation in HRQoL (R(2) = .56). Consequences (β = -.50) and treatment control (β = .20) were associated with HRQoL (the CRQ’s physical domain). They explained 59% of the variation in the CRQ physical (R(2) = .59) domain. Treatment control (β = .19) and emotional response (β = -.33) were associated with the CRQ emotional domain. CONCLUSIONS: Patients who experience fewer symptoms attributed to COPD, who have a better understanding of the disease, who experience less impact of COPD in daily life, who experience better treatment control and who have less of an emotional response have better HRQoL. This study indicates that the HRQoL of COPD patients is associated with illness perceptions as well as with the severity of dyspnoea as experienced by patients. Airflow limitation measures or comorbidities do not add to the explanation of HRQoL. The results of this study provide starting points for the development of interventions focusing on illness perceptions to support COPD patients in their disease management and to improve HRQoL.