Depression and the Risk of All‐Cause and Cardiovascular Mortality in Patients With Chronic Obstructive Pulmonary Disease: A Study From NHANES 2005–2018

<b>Objective:</b> At present, there is a lack of studies on depression and the likelihood for mortality among those suffering from chronic obstructive pulmonary disease (COPD). This research explores the connection between depression and the risks of overall mortality as well as cardiovascular mortality in individuals with COPD. <b>Methods:</b> A total of 1336 COPD patients from seven cycles of the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2018 were selected. We created a multivariate Cox proportional hazards model and performed a subgroup analysis to investigate the connection between depression and both overall and cardiovascular mortality. Additionally, we used restricted cubic spline (RCS) curves to examine the relationship between depression and both overall and cardiovascular mortality to better reveal the association between the two. The Kaplan-Meier technique was employed to determine the likelihood of survival. <b>Results:</b> Over the course of a mean follow-up period of 91 months, 1336 COPD patients were studied, of which 340 patients experienced overall mortality, and 82 had cardiovascular-related deaths. Using RCSs, we found that depression was positively correlated with both all-cause and cardiovascular mortality in COPD patients. In the multivariable-adjusted model, individuals suffering from moderate to severe depression had a greater likelihood of overall and cardiovascular mortality compared to those without depression. The results were consistent in subgroup analyses based on age, gender, body mass index (BMI), and poverty income ratio (PIR), and there was no significant interaction between these traits and depression (<i>p</i> for interaction > 0.05). <b>Conclusion:</b> In COPD patients, depression is associated with higher risks of both cardiovascular and overall mortality. However, further validation of this finding is needed in large-scale prospective studies with sufficient follow-up time.