Table 3.
Conditional logistic regression of the frequency of receiving an influenza vaccination.
| Variable | N | No. of Pneumonia | Crude OR | 95% C.I. | Adjusted OR † | 95% C.I. | |
|---|---|---|---|---|---|---|---|
| Vaccination | |||||||
| 1 yr | 2 yr | ||||||
| No | No | 9882 | 5006 | 1 | 1 | ||
| No | Yes | 1282 | 665 | 1.03 | 0.91–1.17 | 0.98 | 0.86–1.12 |
| Yes | No | 1817 | 908 | 0.96 | 0.86–1.07 | 0.87 * | 0.78–0.98 |
| Yes | Yes | 2149 | 986 | 0.79 ** | 0.71–0.88 | 0.75 ** | 0.67–0.85 |
| Vaccination | |||||||
| Never | 9243 | 4685 | 1 | 1 | |||
| Three consecutive years | 1096 | 475 | 0.64 ** | 0.53–0.77 | 0.56 ** | 0.45–0.69 | |
† Adjusted for hypertension, diabetes, cerebrovascular disease, renal disease, liver disease, ischemic heart disease, dementia, alcohol-related disorder, and malignancy. 1 yr: receive influenza vaccine in the first year before the pneumonia diagnosis. 2 yr: receive influenza vaccine in 1 to 2 years before the pneumonia diagnosis. * p < 0.05, ** p < 0.01.