Cognitive impairment and clinical characteristics in patients with COPD

Abstract

Background: Cognitive impairment (CI) is common in patients with chronic obstructive pulmonary disease (COPD). However, it remains unknown whether and to what extent clinical characteristics are able to differentiate patients with COPD with and without CI. Aims: To investigate the relationship between CI and disease severity, and to study potential differences in exercise performance, problematic daily activities, health status and psychological well-being between patients with and without CI. Methods: Patients with clinically stable COPD referred for pulmonary rehabilitation underwent a comprehensive neuropsychological examination. Functional exercise capacity (six-minute walk test (6MWT)), daily activities (Canadian Occupational Performance Measure (COPM)), disease-specific health status (COPD Assessment Test (CAT), and psychological wellbeing (Hospital Anxiety and Depression Scale (HADS), and Beck Depression Inventory (BDI)) were compared between patients with and without CI. Results: Out of 183 patients with COPD (mean age 63.6 (9.4) years, FEV 1 54.8 (23.0)% predicted), 76 patients (41.5%) had CI and the prevalence did not differ between traditional GOLD stages I-IV (44.8%, 40.0%, 41.0%, 43.5% respectively, p=0.97) and updated GOLD groups A-D (50.0%, 44.7%, 33.3%, 40.2% respectively, p=0.91). Age, gender, educational level, smoking status, mMRC score, FEV 1 % predicted, as well as 6MWT, COPM, CAT, HADS, and BDI scores were comparable between patients with and without CI. Conclusions: Clinical characteristics of COPD patients with and without CI are comparable. Assessment of CI, therefore, requires an active screening approach across all GOLD stages.