COPD ups risk for all-cause mortality

Patients with chronic obstructive pulmonary disease (COPD) are at significantly increased risk for all-cause mortality compared to those without COPD, with lung cancer and chronic lower airway disease being the leading causes of death in at-risk patients, particularly those aged <60 years, reveals a study.

“Our national cohort study provided important observation data to further elucidate the need of early diagnosis and management of COPD with attention to its related comorbidities, especially in younger patients,” the researchers said.

This nationwide retrospective cohort study included 340,767 adults aged 40–84 years who lacked COPD diagnosis at baseline between 1 January 2003 and 31 December 2013. Incident COPD was defined by reference to COPD claim codes and prescription of COPD medication at least twice annually.

The researchers then compared Cox proportional hazard ratio (HR) for each cause of death in the COPD group to that of the non-COPD group, with other causes of death accounted as the competing risk.

Of the participants, 8,227 (2.4 percent) developed COPD during follow-up. Patients who developed COPD were older, more likely to be male, current smoker, to have lower income and more comorbidities at baseline compared to those without COPD. [Respirology 2020;25:726-734]

The rate of all-cause mortality was significantly higher in the COPD than in the non-COPD group (2,978 vs 629 per 100,000 person-years; adjusted HR, 1.41, 95 percent confidence interval [CI], 1.32–1.50). This association was more robust for chronic lower airway disease (adjusted sub-HR, 9.67, 95 percent CI, 7.21–12.96) and lung cancer (adjusted sub-HR, 3.16, 95 percent CI, 2.68–3.71), as well as in those aged <60 years.

“We confirm that COPD is a major cause of premature death, imposing a high societal economic burden. In fact, COPD is the fifth leading cause of loss of disability‐adjusted life years,” the researchers said. [Lancet Respir Med 2017;5:691-706; Lancet 2018;392:1859-1922]

“However, many COPD patients remain undiagnosed in communities, which is significantly higher than undiagnosed patients of other prevalent chronic diseases such as diabetes and hypertension,” they added. [Lancet Respir Med 2017;5:426-434; Lancet Respir Med 2017;5:367-368]

The findings of the current study were also consistent with those of a recent systematic review, which found that COPD patients had a higher risk for cardiovascular disease, cerebrovascular disease, endocrine and metabolic disorders, psychiatric and neurological disorders, gastrointestinal diseases, musculoskeletal disorders, non-COPD respiratory conditions, and cancer than non-COPD controls. [Medicine 2017;96:e6836]

In addition, earlier studies reported that COPD patients with comorbidities had poor clinical outcomes and higher mortality compared with those without comorbidities. Lung cancer was one of the most common comorbidity and the leading cause of death in mild-to-moderate COPD patients. [Eur Respir J 2006;28:1245-1257; Respir Med 2013;107:1376-1384; Arch Intern Med 2003;163:1475-1480; Eur Respir J 2009;34:380-386; Am J Respir Crit Care Med 2007;176:285-290]

“Both public health professionals and clinicians need to put more efforts on COPD screening and management to minimize the burden of disease,” the researchers said.