Table 2. nH1N1 prevalence estimates by adjustment method and age-group, New York City, May 1 to June 19, 2009.
Combined Data May 1–June 19 | Adjustment Method 1* | Adjustment Method 2** | |||||
Estimated ILI Percent Prevalence (95% CI) | Estimated Percent Background ILI (95% CI) | Estimated Percent nH1N1 Prevalence (95% CI) | Estimated Number with nH1N1 (95% CI) | Estimated Percent Background ILI (95% CI) | Estimated Percent nH1N1 Prevalence (95% CI) | Estimated Number with nH1N1 (95% CI) | |
NYC | 15.8 (13.2–19.0) | 8.0 (5.9–10.9) | 7.8 (4.4–10.5) | 639,000 (367,000–880,000) | 3.6 (3.1–4.3) | 12.2 (10.1–14.6) | 1,017,000 (848,000–1,231,000) |
Age-Group | |||||||
0–17 years | 26.6 (20.1–34.0) | 13.5 (8.4–21.5) | 13.1 (4.5–20.2) | 250,000 (87,000–388,000) | 6.6 (5.0–8.5) | 20.0 (15.1–25.5) | 383,000 (290,000–488,000) |
18–64 years | 13.2 (10.2–17.2) | 6.6 (4.4–9.9) | 6.6 (2.6–9.4) | 355,000 (156,000–548,000) | 2.5 (2.0–3.2) | 10.8 (8.3–14.0) | 582,000 (446,000–758,000) |
65+ years | 8.8 (6.2–12.6) | 5.6 (3.0–9.8) | 3.2 (0.0–6.5) | 34,000 (0–68,000) | 3.7 (2.6–5.4) | 5.1 (3.6–7.2) | 53,000 (37,000–75,000) |
*Adjustment Method 1 uses survey 1 data from the less affected boroughs to estimate background ILI.
**Adjustment Method 2 uses emergency department visit data for ILI from 2004–2008 to estimate background ILI.