Table 6.
Logistic Regression with Variables Significantly Related to Type of Institution or Survival to Create the Propensity Score for Treatment at an Academic Hospital
| Risk Factor | Coefficient (SE) | Wald χ2 | Odds Ratio | 95% CI for Odds Ratio | P Value |
|---|---|---|---|---|---|
| Current smoker | −0.47 (0.26) | 3.17 | 0.63 | 0.37–1.05 | .075 |
| Metro zip code | −0.22 (0.07) | 10.57 | 0.81 | 0.71–0.92 | .001 |
| Age at diagnosis, per year | −0.02 (0.01) | 2.32 | 0.98 | 0.97–1.00 | .128 |
| Distance from home, per 100 miles | 0.13 (0.11) | 1.27 | 1.13 | 0.91–1.41 | .260 |
| Income, per $10,000 | 0.04 (0.09) | 0.20 | 1.04 | 0.87–1.25 | .655 |
| Currently married | 0.16 (0.27) | 0.37 | 1.18 | 0.69–2.00 | .545 |
| Arthritis | −0.38 (0.39) | 0.93 | 0.69 | 0.32–1.48 | .335 |
| Lung disease | −0.74 (0.40) | 3.45 | 0.48 | 0.22–1.04 | .063 |
| Radiation with chemotherapy | 1.05 (0.27) | 15.48 | 2.87 | 1.70–4.85 | <.001 |
| Tumor site | |||||
| Oral cavity/oropharynx [reference] | 1.00 | ||||
| Hypopharynx/larynx | −0.82 (0.31) | 7.05 | 0.44 | 0.24–0.81 | .008 |
| Sinus/nose | 0.06 (0.40) | 0.02 | 1.06 | 0.48–2.31 | .887 |
| Other | 0.29 (0.50) | 0.34 | 1.33 | 0.51–3.52 | .562 |
Stage was excluded from the analysis due to the degree of missing information. Abbreviations: CI, confidence interval; SE, standard error.