Table 4.
Univariate and multivariate analyses for factors associated with total seroconversion for 2009 pandemic influenza A (H1N1) in 90 unvaccinated healthcare workers at a children' hospital in Taiwan
| Characteristics | No. (median/mean) | Crude OR (95% CI) | P value | Adjusted OR (95% CI) | P value |
|---|---|---|---|---|---|
| Age per 10 years1 | (29.2/31) | 1.45 (0.71-2.93) | 0.305 | ||
| Male sex | 18 | 0.69 (0.14-3.45) | 0.654 | ||
| Baseline anti-H1N1 titer2 | (10.0/12.3) | 0.36 (0.07-2.01) | 0.245 | ||
| High risk group3 | 40 | 3.34 (0.94-11.80) | 0.061 | 6.51 (1.13-37.52) | 0.036 |
| Optimal surgical mask usage | 75 | 3.39E8 (0.00-∞) | 0.998 | ||
| Optimal hand hygiene | 83 | 3.00E8 (0.00-∞) | 0.999 | ||
| ILI episode | 21 | 12.19 (3.23-46.04) | < 0.001 | 9.14 (2.02-41.36) | 0.004 |
| Virologically confirmed 2009 H1N1 infection4 | 9 | 11.41 (2.54-51.32) | 0.002 | 5.99 (0.98-36.48) | 0.052 |
Abbreviations: OR, odds ratio; CI, confidence interval; ILI episode, influenza-like illness episode.
1 For every 10-year increase in age, for which integer values 0-3 denote ages of 20-30, 30-40, 40-50, and 50-60, respectively.
2 Unit increase in baseline titer, for which integer values 0-8 denote titers of < 10, 10, 20, 40, 80, 160, 320, 640, and 1280 or more, respectively.
3 HCWs in direct contact with patients with 2009 pandemic influenza A (H1N1) infection or their respiratory samples were designated high-risk group.
4 Virologically confirmed means either viral isolation or real time polymerase chain reaction was positive of 2009 H1N1 influenza virus.