Demographics of community cohort of adults ≥50 years old and RSV infected patients for all seasons combined (2006–07 to 2009–10).

1There were 20,453 unique individuals who were included in the cohort for at least 1 of the 4 seasons. Of these 13,355 (65%) were in all 4 seasons; 2452(12%) were in 3 seasons, and 2313(11%) were in two seasons.2Chronic obstructive pulmonary disease (COPD) defined having an ICD-9 code within the range of 491.001–492.999 in the years 2005 to 2010 for cohort or prior to the study season for RSV cases.3Congestive heart failure (CHF) defined as having an ICD-9 code within the range of 428.001–428.9 in the years 2005 to 2010 for cohort or prior to the study season for RSV cases.