Domain-specific cognitive impairment in patients with COPD and control subjects

Abstract

Background: Cognitive impairment may interfere with disease-management in patients with chronic obstructive pulmonary disease (COPD), depending on which cognitive domains are affected. The prevalence of domain-specific cognitive impairment in patients with COPD entering pulmonary rehabilitation remains unknown. Aim: To compare the prevalence of domain-specific cognitive impairment between patients with COPD and non-COPD controls. Methods: A neuropsychological assessment was administered in stable COPD patients and controls with comparable smoking status, age, and education. Six tests from the Maastricht Aging Study were used to assess general cognitive impairment. Compound Z scores were constructed for psychomotor speed, planning, working memory, verbal memory, and cognitive flexibility. Results: 90 COPD patients (mean age 63.7 (SD 8.8) yrs; 54.4% men; FEV 1 54.5% (23.7) pred.) and 90 controls (mean age 62.3 (SD 7.4) yrs; 50.0% men; FEV 1 116.3% (18.2) pred.) were included. General cognitive impairment was found in 56.7% and 13.3% of COPD patients and controls, respectively (p<0.001). In patients, all cognitive domains were more affected than in controls. Conclusions: General and domain-specific cognitive impairment affects patients with COPD to a higher degree than controls. Clinicians should be aware of the possible presence of cognitive impairment and disease-management programs should take into account the needs of these patients.