Table 2.
Estimated Annual Incidence Rates of Hospitalization for Community-Acquired Pneumonia, According to Year of Study, Study Site, Age Group, and Pathogen Detected.*
| Variable | Incidence of Pneumonia-Related Hospitalization (95% CI) |
|---|---|
| no. of cases per 10,000 adults per yr | |
|
| |
| Year of study† | |
|
| |
| Yr 1 and 2 | 24.8 (23.5–26.1) |
|
| |
| Yr 1 | 29.2 (27.2–31.2) |
|
| |
| Yr 2 | 20.6 (19.1–22.3) |
|
| |
| Study site | |
|
| |
| Chicago | 26.7 (25.0–28.4) |
|
| |
| Nashville | 21.9 (20.0–23.8) |
|
| |
| Age group | |
|
| |
| 18–49 yr | 6.7 (6.1–7.3) |
|
| |
| 50–64 yr | 26.3 (24.1–28.7) |
|
| |
| 65–79 yr | 63.0 (56.4–70.3) |
|
| |
| ≥80 yr | 164.3 (141.9–189.3) |
|
| |
| Pathogen detected‡ | |
|
| |
| Human rhinovirus | 2.0 (1.7–2.3) |
|
| |
| Influenza A or B virus | 1.5 (1.3–1.8) |
|
| |
| Streptococcus pneumoniae | 1.2 (1.0–1.4) |
|
| |
| Human metapneumovirus | 0.9 (0.7–1.2) |
|
| |
| Parainfluenza virus | 0.8 (0.6–1.0) |
|
| |
| Respiratory syncytial virus | 0.7 (0.5–0.9) |
|
| |
| Coronavirus | 0.6 (0.4–0.7) |
|
| |
| Mycoplasma pneumoniae | 0.5 (0.4–0.7) |
|
| |
| Staphylococcus aureus | 0.4 (0.3–0.6) |
|
| |
| Legionella pneumophila | 0.4 (0.2–0.5) |
|
| |
| Adenovirus | 0.4 (0.2–0.5) |
Analyses were based on 10,511,911 person-years of observation.
Annual incidence rates were calculated from July 1, 2010, to June 30, 2011, for year 1 and from July 1, 2011, to June 30, 2012, for year 2 and represent the 2061 of 2320 adults (89%) who had radiographic evidence of pneumonia and were enrolled during that time.
Pathogen-specific incidence was calculated for the 2004 adults who had radio-graphic evidence of pneumonia during the incidence period and who had at least one specimen available for both bacterial and viral testing. Pathogen-specific incidence was only calculated for pathogens that were detected in more than 1% of adults.