Table 4.
Multivariable Model*
| n (Vaccine Strains) | n (Women) | % Seroconversion | Odds Ratio (95% CI) | |
|---|---|---|---|---|
| Age group (p=.31) | ||||
| Younger than23 | 192 | 90 | 63.5 | ref |
| 23-29 | 179 | 86 | 63.7 | 1.06 (0.62-1.78) |
| 30 or older | 136 | 63 | 53.7 | 0.68 (0.38, 1.21) |
| Education (p=.12) | ||||
| Less than high school | 162 | 75 | 57.4 | 0.89 (.53-1.52) |
| High school | 97 | 46 | 73.2 | 1.66 (.93-3.0) |
| Post-high school | 248 | 118 | 58.5 | ref |
| Obese (p=.16) | ||||
| Nonobese | 371 | 173 | 64.4 | ref |
| Obese | 136 | 66 | 51.5 | 0.68 (0.41-1.14) |
| Baseline hemagglutinin inhibition titer (p<.001) | ||||
| 0-20 | 354 | 204 | 69.8 | ref |
| 40 | 85 | 71 | 57.7 | 0.42 (.23-.74) |
| 80 or higher | 68 | 50 | 19.1 | 0.07 (0.03, 0.16) |
| Self-reported receipt of influenza vaccine in the prior year (p=.03) | ||||
| Yes | 153 | 71 | 48.4 | 0.51 (.30-.85) |
| No | 321 | 154 | 66.7 | ref |
| Uncertain | 33 | 14 | 63.6 | 1.32 (.45-3.84) |
| Vaccine strain by year (p<.001) | ||||
| 2006/2007 A/New Caledonia/20/99 | 35 | 62.9 | ||
| 2006/2007 A/Wisconsin/67/2005 | 35 | 37.1 | ||
| 2007/2008 A/Wisconsin/67/2005 | 50 | 64 | ||
| 2007/2008 A/Solomon Islands/03/2006 | 50 | 78 | ||
| 2008/2009 A/Brisbane 10/2007 | 68 | 64.7 | ||
| 2009/2010 A/Brisbane 10/2007 | 75 | 56 | ||
| 2008/2009 A/ Brisbane 59/2007 | 67 | 58.2 | ||
| 2009/2010 A/ Brisbane 59/2007 | 76 | 61.8 | ||
| 2009 Pandemic A/California 04/2009 | 51 | 60.8 |
*
P-values are for each term, adjusting for all other terms in the model.