Table 3

Harrell’s c-statistic for discrimination ability of Cox proportional hazards models on 3-year overall survival of women aged 50+ years with ER-positive EIBC by country of diagnosis

Model no.Factors included in the cox regression model for 3 year survivalHarrell’s c-statistic for cox proportional hazards survival model
England (internal validation)Wales (external validation)
In all women*In women who did receive surgeryIn women who did not receive surgeryIn all women*In women who did receive surgeryIn women who did not receive surgery
1Invasive grade, T stage, N stage, HER2 status, IMD status
(+receipt of surgery*)
0.8040.6690.5520.7820.6340.653
2Invasive grade, T stage, N stage, HER2 status, IMD status+CCI (+receipt of surgery*)0.8240.7080.6180.8020.6640.679
3Invasive grade, T stage, N stage, HER2 status, IMD status+SCARF index (+receipt of surgery*)0.8280.7180.6250.8040.6670.691
4Invasive grade, T stage, N stage, HER2 status, IMD status+CCI+SCARF index (+receipt of surgery*)0.8290.7190.6280.8050.6730.690
5Invasive grade, T stage, N stage, HER2 status, IMD status+age (+receipt of surgery*)0.8420.7500.6380.8370.7230.703
6Invasive grade, T stage, N stage, HER2 status, IMD status+CCI+SCARF index+age (+receipt of surgery*)0.8520.7700.6630.8410.7340.715
  • *The receipt of surgery was only factored in the model that included all women.

  • CCI, Charlson Comorbidity Index; EIBC, early invasive breast cancer; HER2, Human epidermal growth factor receptor 2; IMD, Index for multiple deprivation; SCARF, secondary care administrative records frailty.