TABLE 2.
Population Size, Outcome, and Explanatory Variables (Weighted Average of All 5 Seasons): United States, 2000–2005
| Influenza Season | Entire Community-Dwelling Elderly Population | Unvaccinated Subpopulation at an Epidemic Start |
| Population size, unweighted no. (weighted no.) | ||
| 2000–2001 | 4675 (14.9 million) | 2597 (8.31 million) |
| 2001–2002 | 4795 (15.8 million) | 2503 (8.29 million) |
| 2002–2003 | 4834 (16.1 million) | 2280 (7.69 million) |
| 2003–2004 | 4672 (16.1 million) | 2822 (9.74 million) |
| 2004–2005 | 4565 (16.4 million) | 2621 (9.60 million) |
| Influenza vaccine receipt,a % | 48.5% | 8.77% |
| Explanatory variables | ||
| Regional factors | ||
| Influenza epidemic levelb (% of specimens testing positive for influenza) | 8.56 (0.120) | 16.2 (0.220) |
| Vaccine dose distributed in past 4 wkb (in millions) | 7.33 (7.19E-3) | 2.37 (0.141) |
| Individual factors, % | ||
| Female | 0.580 | 0.571 |
| Age ≥ 75 y | 0.515 | 0.489 |
| Race: other than White | 0.131 | 0.167 |
| Education: high school diploma | 0.696 | 0.666 |
| Income: ≥ $20 000 per y | 0.542 | 0.505 |
| Subjective general health status: fair/poor | 0.218 | 0.222 |
| High-risk chronic conditions for flu | 0.513 | 0.473 |
| Private supplemental health insurance: Medigap | 0.741 | 0.680 |
| Medicaid enrollment | 0.119 | 0.149 |
| Household number ≥ 2 | 0.680 | 0.676 |
| Metropolitan residence | 0.721 | 0.723 |
| Current smoking | 0.105 | 0.120 |
| Avoid medical care when sick | 0.267 | 0.291 |
| See physician soon when sick | 0.343 | 0.339 |
| Presence of physician one regularly consults with | 0.807 | 0.775 |
a
Outcome variable.
b
Weekly, at the 9 census region level.