Table 2– Univariate and multivariate Cox regression analysis evaluating the effect of depressive symptoms and significant confounders on 1-year mortality

Variable	Univariate analysis		Multivariate analysis
Variable	HR (95% CI)	p-value	HR (95% CI)	p-value
Age	0.990 (0.949–1.032)	0.624
Male sex	1.748 (0.415–7.363)	0.447
BMI	0.962 (0.906–1.020)	0.193
Smoking status (current)	0.547 (0.222–1.348)	0.190
Charlson comorbidity index	1.201 (0.904–1.596)	0.206
GOLD COPD stage	3.696 (2.191–6.233)	<0.001	2.919 (1.632–5.220)	<0.001
MRC dyspnoea score	1.244 (0.812–1.905)	0.316
Depressive symptoms	7.605 (2.891–20.006)	<0.001	3.568 (1.302–9.780)	0.013

BMI: body mass index; GOLD: Global Initiative for Chronic Obstructive Lung Disease; COPD: chronic obstructive pulmonary disease; MRC: Medical Research Council.