Viral Etiology of Chronic Obstructive Pulmonary Disease Exacerbations during the A/H1N1pdm09 Pandemic and Postpandemic Period

Table 1

Inclusive study periods.

Period	Description	Duration
PAN	2009 pandemic	Week 35, 2009–week 32, 2010
INEP1	Interepidemic 2010	Week 33, 2010–week 39, 2010
FLUEP1	Influenza epidemic 2010-11	Week 40, 2010–week 20, 2011
INEP2	Interepidemic 2011	Week 21, 2011–week 39, 2011
FLUEP2	Influenza epidemic 2011-12	Week 40, 2011–week 20, 2012
INEP3	Interepidemic 2012	Week 21, 2012–week 39, 2012