Study Population
During the study period, 4,232 adults were hospitalized with a
laboratory-confirmed respiratory virus and met the community-onset case
definition. Testing for a respiratory virus occurred on hospital day 1
for 90.7% of patients, on hospital day 2 for 5.0% of patients, on
hospital day 3 for 2.0% of patients, and 2.3% of patients had testing
performed in ambulatory settings affiliated with the hospitals.
Selected demographic characteristics and the distribution of the zip
codes of patients are shown in Table 1. Demographic characteristics were
similar in year 1 and year 2; 50.9% of patients were> 65 years of age and 23.5% of patients were> 80 years of age. Overall, 2,447 (57.8%) of
patients resided in zip codes that represented > 60%
of the hospital’s market share.