Table 1.

Cox proportional hazards model for time to first tumor indicates that the SeMet group had lower risk than controls. Males had slightly higher risk, although this was not statistically significant. A goodness of fit test using only the treatment factor (SeMet or Control using the cox.zph function) gives p = 0.68 indicating no violation to the proportional hazards assumption.

Predictor	Coefficient	Hazard Ratio	Lower 95% CI	Upper 95% CI	Z	p-value
Group = SeMet	−0.5182	0.5956	0.3668	0.9672	−2.095	0.036
Sex = m	0.2364	1.2667	0.7840	2.0464	0.966	0.33