Cognitive Impairment in Patients with Severe COPD: A Cross-Sectional Study

Background/Objectives: Cognitive impairment (CI) in patients with chronic obstructive pulmonary disease (COPD) has been associated with reduced physical activity and decreased adherence to inhalation therapy. The primary aim of this study is to examine the prevalence of CI in patients with severe COPD and secondly compare outcomes with non-COPD comparators. Methods: Patients with severe COPD defined as forced expiratory volume in first second (FEV₁) <50% were recruited between January 2021 to January 2023 along with non-COPD comparators. CI was defined as a MoCA score < 26, adding one point for participants with ≤12 years of education. Additionally, two functional cognitive tests were included: the Continuous Reaction Time test (CRT) and a driving simulator. Results: Eighty patients with COPD (mean age 64 years) and 22 non-COPD comparators (mean age 61 years) participated. CI was identified in 32 patients with COPD (40%) and six non-COPD comparators (27%) with a 0.87 non-significant difference (95% CI: -0.15-1.88). The functional tests showed a 0.267 difference in CRT index (95% CI: 0.023-0.511) and a 0.056 difference in standard deviation from center of the road (95% CI: 0.002-0.11) revealing a significantly poorer performance in functional tests among patients compared to non-COPD comparators. Nineteen patients with COPD and one non-COPD comparator failed the driving test (p = 0.04). Conclusions: CI was found in 40% of patients with severe COPD based on MoCA score. While MoCA score did not differ between the two groups, functional tests demonstrated significantly reduced abilities in patients compared with non-COPD comparators.