Table 2.
Logistic Regression Analysis of Rates of Decline of Anti-EGFR Use, and the Effect of Demographic Characteristics on These Rates
| Predictor | Odds Ratio Estimate | P |
|---|---|---|
| Time period | ||
| Before time 1 | Ref | |
| Time 1-time 2 (June 2008-February 2009) | 0.87 | .003 |
| Time 2-time 3 (February 2009-August 2009) | 0.87 | .03 |
| Time 3-time 4 (August 2009-April 2010) | 0.83 | .02 |
| Charlson comorbidity score | ||
| 0 | Ref | |
| 1 | 0.81 | .11 |
| 2 | 1.0 | .97 |
| ≥ 3 | 0.8 | .32 |
| Sex | ||
| Female | Ref | |
| Male | 1.2 | .06 |
| Age (continuous variable) | 0.99 | .1 |
| Region | ||
| West | Ref | |
| East | 1.1 | .5 |
| Midwest | 1.2 | .4 |
| South | 1.3 | .2 |
Abbreviations: EGFR, epidermal growth factor receptor; Ref, reference.