Table 2.

Multivariate Cox proportional hazards analyses for covariates from 2 validated Cox proportional hazards models, refitted using our source population data^*

Model and covariates†	Hazard ratio	95% Confidence interval
Chow’s 3-variable NRF (C-3) model7
Primary cancer site
Breast	1.00	-
Nonbreast	1.75	1.34–2.29
KPS
>60	1.00	-
<60	3.7	2.88–4.75
Site of metastases
Bone only	1.00	-
Other	2.25	1.79–2.82
Westhoff’s 2-variable (W-2) model8
Primary cancer site
Breast	1.00	-
Prostate	1.17	0.78–1.75
Lung 2.57 1.89–3.49
Other 2.05 1.53–2.77
KPS
90–100	1.00	-
70–80	1.81	1.37–2.40
20–60	6.17	4.41–8.58

Abbreviations: KPS = Karnofsky Performance Status; NRF = number of risk factors.

^*A complete data set with no missing values for the covariates was used to refit the models.

^†Covariate values are specified as per the source model’s definitions.