Table 6. Marginal effect of cetuximab on infection event using instrumental variable analysis for one-year follow-up (n = 611).
| Odds ratio | (95%CI) | P-value | |
| Cetuximab | 0.87 | (0.61–1.14) | 0.319 |
| Age, yrs | 1.00 | (0.95–1.21) | 0.052 |
| Male | 1.08 | (1.00–1.01) | 0.248 |
| Charlson ComorbidityIndex Score | |||
 1 |
1.02 | (0.97–1.08) | 0.368 |
| Socioeconomic status | |||
High ( NT$20001 or US$626 ) |
0.95 | (0.89–1.01) | 0.076 |
| Urbanization level | |||
| Rural | 0.99 | (0.93–1.04) | 0.614 |
| Region | |||
| Southern/Eastern | 1.02 | (0.95–1.09) | 0.604 |
| Treatment | |||
| Chemotherapy/Chemotherapy+Radiotherapy | 0.99 | (0.94–1.04) | 0.755 |
Abbreviation: 95% CI, 95% confidence interval.