Trajectories of Severe Exacerbations of Chronic Obstructive Pulmonary Disease and Their Relationship with Mortality Risk.

Abstract

Acute exacerbations of COPD (AECOPD) are important factors contributing to mortality risk. The rate of exacerbations varies overtime. An inconsistent pattern of exacerbation occurrence is a common finding. The mortality risk associated with such a pattern is not entirely clear. Our objective was to assess the risk of mortality associated with various possible patterns of AECOPD trajectories. This is a multicenter historical cohort study. Four different exacerbation trajectories were defined according to the incidence of severe AECOPD requiring hospital admission 2years before and after the date of the first visit to the respiratory clinic-Consistent non-exacerbators (NEx): no AECOPD before or after the index date; consistent exacerbators (Ex): at least one AECOPD both before and after the index date; converters to exacerbators (CONV-Ex): no exacerbations before and at least one AECOPD after the index date; converters to non-exacerbators (CONV-NEx): at least one AECOPD before the index date, and no exacerbations after said date. All-cause mortality risk for these trajectories was assessed. A total of 1713 subjects were included in the study: NEx: 1219 (71.2%), CONV-NEx: 225 (13.1%), CONV-Ex: 148 (8.6%), Ex: 121 (7.1%). After correcting for confounding variables, the group with the highest mortality risk was Ex. The CONV-Ex and CONV-Nex groups had a mortality risk between Ex and NEx, with no significant differences between them. Different possible trajectories of severe AECOPD before and after a first specialized consultation are associated with different mortality risks. An inconsistent pattern of exacerbations has a mortality risk between Ex and NEx, with no clear differences between CONV-Ex and CONV-NEx.