Table 4.
Results of GAM and proportional hazards tests for GBSG-2 data
| GBSG-2 data set | no transform | transform age+|age-50|1.5 | transform age+|age-50|1.8 |
| Hazard ratio for Age | 1.001 | 1.004 | 1.002 |
| p-value of Hazard ratio for Age | 0.92 | 0.019 | 0.010 |
| GAM Chisq for Age | 31.74 | 9.29 | 8.70 |
| GAM p-value for Age | 0.0000006 | 0.0256 | 0.0336 |
| Test PH for Age: rho | 0.131 | 0.0459 | 0.0240 |
| Test PH for Age: chisq | 6.118 | 0.581 | 0.169 |
| Full PH model Rsquare | 0.135 | 0.142 | 0.143 |
| Full PH model Likelihood ratio test | 99.7 | 105 | 106 |
Chisq = chi-square value, GAM = generalized additive model, GBSG-2 = German Breast Cancer Study Group, PH = proportional hazards. The Additional file 2 "outputgbsg2.doc" lists the other covariates included in the PH models.