Table 2. Estimated Annual Incidence Rates^* of Community-acquired Pneumonia Hospitalization by Year, Site, Age Group, and Pathogen Detected.

Variable	Annual no. pneumonia hospitalizations/10,000 children	95% confidence interval
Overall incidence rate†	15.7	14.9–16.5
2010-2011 (year 1)	16.8	15.6-18.0
2011-2012 (year 2)	14.6	13.5-15.7
Study Site
Memphis	19.6	18.0–21.3
Nashville	12.3	11.2–13.4
Salt Lake City	15.2	13.8–16.5
Age group
<2 years	62.2	57.6–67.1
2-4 years	23.8	21.4–26.3
5-9 years	10.1	8.9–11.3
10-17 years	4.2	3.6–4.8
Pathogen-specific incidence‡
Respiratory Syncytial Virus	4.6	4.3–5.1
Human Rhinovirus	4.1	3.7–4.4
Human Metapneumovirus	1.9	1.6–2.1
Adenovirus	1.6	1.4–1.8
Mycoplasma pneumoniae	1.4	1.2–1.6
Influenza A/B virus	1.1	0.9–1.3
Parainfluenza viruses 1-3	0.9	0.8–1.1
Coronaviruses	0.8	0.7–1.0
Streptococcus pneumoniae	0.5	0.4–0.6

^*Based on 2,212,327 person-years of observation

^†Annual incidence rates were calculated from July 1, 2010 to June 30, 2011 (year 1) and July 1, 2011 to June 30, 2012 (year 2) and represent the 2012 children with radiographic pneumonia enrolled during that time

^‡Pathogen-specific incidence is calculated for the 1899 children with radiographic pneumonia during the incidence period with at least one specimen available for both bacterial and viral testing. Age-specific pathogen-specific incidence is in Supplementary Table S6.