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Seasonal and Regional Variations in COPD Exacerbation Rates in Adults without Cardiovascular Risk Factors.
Ann Am Thorac Soc. 2018 Jul 31;:
Authors: So JY, Zhao H, Voelker H, Reed RM, Sin D, Marchetti N, Criner GJ, COPD CRN investigators
Abstract
RATIONALE: Colder temperatures have been shown to increase hospitalization and mortality rates in adults with COPD and cardiac disease. Seasonal influences on exacerbation rates in adults with severe COPD but without significant cardiovascular disease are unclear. In addition, regional variations in COPD exacerbations in North America have not yet been explored.
OBJECTIVES: In this study, we sought to determine the seasonal and regional variability in exacerbation rates in those with COPD but without significant cardiovascular risk factors.
METHODS: We studied adults without cardiovascular risk factors from the STATCOPE and placebo arm of MACRO studies. Forty-five study sites were divided into climate regions in Canada and the United States; seasons were defined as winter, spring summer and fall. The primary outcome was the rate of COPD exacerbation. Secondary outcomes included time to first exacerbation, severity of exacerbations, all-cause mortality, and antibiotic and steroid use.
RESULTS: We analyzed 1175 subjects with a mean age of 63.3 ± 8.6 years, FEV1 41.5 ± 17.1% predicted and 53.6 ± 29.4 pack-years of smoking history. The COPD exacerbation rate was higher in winter (0.13 exacerbations/person-month) than in spring, summer, and fall (0.11, 0.079, 0.10 exacerbations/person-month respectively) (p <0.001). Summer had the highest proportion of severe exacerbations (40.5%) compared to spring, fall, winter (32.6%, 34.7%, 33.1% respectively) (p=0.004). Mortality was highest in spring and winter (34 and 30% respectively). There was significant regional variability in the time to first exacerbation, with the Southeast and West having longer median times to first exacerbation (350 and 342 days respectively compared to 184 days in other regions) (p<0.001).
CONCLUSION: Significant seasonal and regional variability exists in the rates and severity of exacerbations and overall mortality in adults with COPD without cardiovascular disease.
PMID: 30063372 [PubMed - as supplied by publisher]