Experiencing One or More COPD Exacerbations Linked to Increased Mortality

Patients who experienced one or more acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in a year were not associated with 30 day mortality, but were linked to increased 31-365 day mortality, according to research published in BMJ Open.

In a cohort study using medical databases, a global team of researchers identified 6,664 chronic obstructive pulmonary disease (COPD) patients with at least 1 AECOPD during the period between January 1, 2005 and December 31, 2009 in order to examine the link between exacerbation frequency and mortality. AECOPD was defined as “an acute event characterized by a worsening of the patient’s respiratory symptoms that is beyond normal day to day variations and leads to change in medication,” the authors commented. Patients were excluded from the cohort if they did not experience AECOPDs within the study period or were under the age of 40 years. Emergency room diagnoses of COPD or AECOPD were also not included — the researchers only included those patients admitted to hospitals for treatments, as aligned with Danish practice guidelines.

On average, patients were aged 70 years, and the population was 53 percent female. Cormobidities were frequent and included cardiovascular disease, diabetes, osteoporosis, and asthma. Patients had also received prescriptions for antibiotics within the prior 3 months (31 percent) and for systemic steroids within the previous 12 months (30 percent).

The patients were monitored from the first AECOPD during this period until their death, emigration, or December 31, 2009 — whichever came first. All AECOPD events were flagged during the follow up period and were characterized by the exacerbation frequency as either 0, 1, 2, or 3+ in the prior 12 month period.

“Because AECOPD is an acute event, we expect the mortality rate to be greatest in the initial phase following the event,” the authors wrote. “We therefore separated the effect of AECOPD on mortality in the first 30 days versus day 31 to day 365 after the event in all mortality rate calculations.”

The researchers determined the 0-30 day mortality rate ratios (MRRs) were 0.97, 0.90, and 1.03 among patients with AECOPD with 1, 2, and 3+ AECOPDs versus no AECOPD within the past 12 months, respectively. For days 31-365, the corresponding MRRs were 1.47, 1.89, and 1.59 for patients with 1, 2, and 3+ AECOPDs, respectively.

“A history of at least one AECOPD in the 12 months before exacerbation may serve as an indicator of a higher mortality rate during 31 to 365 days but not during the first 30 days following the AECOPD,” the authors concluded. “The lack of an effect on 0-30 day mortality may be explained by study factors such as the use of a prevalent cohort of patients with COPD or a higher baseline rate than in the 31-365 day period.”