Table 1. Estimated Influenza Associated Hospitalizations1 with and without Pneumonia by Clinical Outcome, AZ, CA, & WA, January 2003 through March 2009.
| Age (years) | Total Influenza-Associated respiratory & circulatory Hospitalizations2 n, (95% CI) | Influenza-Associated respiratory & circulatory Hospitalizations2 without Pneumonia 3 n, (95% CI) | Total Influenza-Associated critical illness Hospitalizations2 n, (95% CI) | Influenza-Associated critical illness Hospitalizations2 without Pneumonia 3 n, (95% CI) | ||||
| 18–49 | 20,837 | (6,986–42,870) | 8,320 | (402–25,377) | 3,161 | (1,108–6,491) | 1,143 | (122–3,536) |
| 50–64 | 11,842 | (0–32,712) | 3,990 | (0–20,081) | 4,986 | (2,147–10,257) | 1,927 | (378–5,367) |
| 65–74 | 7,012 | (0–31,160) | 1,193 | (0–16,963) | 5,022 | (2,213–9,253) | 1,644 | (356–4,232) |
| 75–84 | 17,197 | (2,021–46,251) | 2,507 | (0–22,850) | 6,553 | (3,039–12,759) | 1,524 | (81–5,489) |
| 85+ | 23,945 | (9,770–42,708) | 8,806 | (1,121–22,373) | 7,038 | (3,533–12,050) | 1,975 | (812–4,562) |
| Overall | 80,834 | (29,214–174,033) | 24,816 | (6,342–92,624) | 26,760 | (14,541–47,464) | 8,213 | (3,764–20,799) |
1. Outcome definitions are detailed in the Table S1. Respiratory and Circulatory Hospitalizations were defined by ICD-9-CM codes for hospitalizations with any respiratory or circulatory diagnoses. Critical illness Hospitalizations were defined by ICD-9-CM diagnosis and procedure codes for hospitalizations with acute respiratory failure, severe sepsis, or in-hospital death.
2. Total influenza-associated events and total influenza-associated events without pneumonia were estimated from negative binomial regression models.
3. Pneumonia defined by ICD-9-CM codes for pneumonia diagnosis codes excluding concurrent influenza diagnosis codes.