Exacerbations Cluster in Time in Chronic Lung Disease
Second exacerbations occur within eight weeks of the first in some patients
FRIDAY, Feb. 27 (HealthDay News) -- Exacerbations cluster together in time in patients with chronic obstructive pulmonary disease, with second exacerbations occurring within eight weeks of the first in about one-quarter of patients, researchers report in the Mar. 1 issue of the American Journal of Respiratory and Critical Care Medicine.
John R. Hurst, Ph.D., and colleagues from the Royal Free and University College Medical School in London, United Kingdom, examined whether exacerbation events were random or clustered in 297 patients with chronic obstructive pulmonary disease.
During 904 patient-years, the researchers found that the timing of a second exacerbation after an initial exacerbation differed significantly from the exponential function that would be expected if the exacerbations occurred randomly. A second exacerbation occurred within eight weeks of a first exacerbation in 27 percent of patients, and about one-third of exacerbations were recurrent, the investigators note. Initial events were just as likely to be treated as isolated events, even though they were milder. A significant portion of the overall exacerbation frequency consisted of recurrent events, the report indicates.
The study "is the first to identify a specific high-risk period for exacerbation occurrence, which may be used to target interventions given to patients during this critical timeframe," Shawn D. Aaron, M.D., from the Ottawa Health Research Institute in Ontario, Canada, writes in an accompanying editorial.
The author of the editorial has reported financial relationships with several pharmaceutical companies.