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

ABSTRACT

PURPOSE: 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. METHODS: This is a multicenter historical cohort study. Four different exacerbation trajectories were defined according to the incidence of severe AECOPD requiring hospital admission 2 years 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. RESULTS: 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. CONCLUSION: 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.