Table 2.

Factors associated with cognitive impairment in univariate and multivariate analysis

Variable	Univariate			Multivariate
	OR	95% CI	P-value	OR	95% CI	P-value
Age (per 5-year increment)	1.177	1.099–1.262	<0.001
Educational level (completed university vs basic literacy)	0.160	0.080–0.310	<0.001	0.069	0.011–0.447	0.014
Postbronchodilator FVC	0.977	0.963–0.991	0.001
Postbronchodilator FEV1	0.975	0.959–0.991	0.003
Cough	2.290	1.540–3.410	<0.001
Expectoration	1.780	1.300–2.430	<0.001
Presence of dyspnea (yes vs no)	2.850	1.360–5.960	0.005
Exacerbations in the previous year (yes vs no)	4.570	2.750–7.570	<0.001
Oxygen therapy	3.180	1.070–9.440	0.037
BODEx	1.280	1.179–1.389	<0.001
Charlson comorbidity index	1.590	1.435–1.762	<0.001
BDI score	1.125	1.098–1.152	<0.001
Suicide ideation	3.150	2.120–4.670	<0.001
Health status according to EQ-5D	0.799	0.742–0.860	<0.001
Social tariff EQ-5D	0.971	0.965–0.977	<0.001	0.967	0.950–0.983	<0.001
CAT score	1.098	1.078–1.118	<0.001
Physical activity grade	0.648	0.587–0.715	<0.001
Minutes walked per day	0.994	0.991–0.998	0.001

Abbreviations: BDI, Beck Depression Inventory; BODEx, Body mass index, airflow Obstruction, Dyspnea and Exacerbations index; CAT, COPD Assessment Test; CI, confidence interval; EQ-5D, EuroQoL-5 dimensions; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; OR, odds ratio.