Long-term prognosis in patients with chronic obstructive pulmonary disease (COPD) is significantly predicted by short-term COPD re-exacerbation, according to study findings published in BMJ Open Respiratory Research.
Exacerbation is a major cause of mortality among patients with COPD, but evidence linking short-term re-exacerbation following discharge and long-term prognosis is limited. Investigators in China therefore conducted a prospective clinical cohort study to assess long-term outcomes and clinical characteristics of patients re-hospitalized with COPD re-exacerbation within 30 days of discharge for an exacerbation of COPD (ECOPD). Primary endpoints were exacerbation, severe exacerbation, and all-cause readmission in the 12 months following an ECOPD discharge.
The study used data from the Acute Exacerbations of Chronic Obstructive Pulmonary Disease Inpatient Registry. This registry, created September 2017, is an ongoing study gathering data from patients with COPD in more than 170 hospitals across mainland China. The current analysis involved patient data collected up to November 2021.
Registry patients at least 18 years of age (N=4963; 21% women; mean [SD] age, 68.89 [9.50] years) were divided into 2 groups based on incidence of re-exacerbation within 30 days of ECOPD discharge: the event cohort (n=242 patients who experienced at least 1 re-exacerbation within 30 days of ECOPD discharge) and the non-event cohort. The investigators defined ECOPD as an event characterized by worsening of dyspnea, cough, and/or sputum production in less than 14 days. An acute episode requiring emergency treatment or hospitalization was defined as a severe exacerbation.
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Re-exacerbation within 30 days of discharge was a significant predictor of future 1-year outcomes, including exacerbation, severe exacerbation, and all-cause readmission, in patients hospitalized with exacerbation of COPD.
The event vs non-event cohort had a significantly greater proportion of patients who had never smoked, fewer patients who currently smoked, and a greater proportion of patients with severe exacerbation within the past year. Patients in the event cohort were also more likely to have comorbid chronic heart failure, to use of home oxygen therapy, to have significantly lower scores for forced expiratory volume in 1 second (FEV1) and significantly higher levels of partial pressure of carbon dioxide in arterial blood (PaCO2).
For all primary study endpoints (ie, exacerbation, severe exacerbation, and all-cause readmission), the event vs non-event cohort had significantly higher cumulative incidence rates and incidence densities in the 12 months following ECOPD discharge. The investigators noted re-exacerbation within 30 days of ECOPD discharge was associated with increased risk for exacerbation (adjusted hazard ratio [aHR], 3.85; 95% CI, 3.09-4.80); severe exacerbation (aHR, 3.46; 95% CI, 2.66-4.50); and all-cause readmission (aHR, 3.28; 95% CI, 2.52-4.25), using multivariate hazard models accounting for the competing risk of death.
The investigators found no significant differences between the event cohort and non-event cohort for the cumulative incidence and incidence density of all-cause mortality or COPD-exacerbation-specific mortality.
Study limitations include lack of clear information on nonsmoking status and significant missing clinical information.
“Re-exacerbation within 30 days of discharge was a significant predictor of future 1-year outcomes, including exacerbation, severe exacerbation, and all-cause readmission, in patients hospitalized with exacerbation of COPD,” the investigators concluded. “This prospective clinical cohort study provides new evidence for identifying the phenotype associated with frequent exacerbation among patients with COPD” and “emphasizes the importance of in-hospital care and outpatient management,” the study authors noted.
