Table 2 Last iterations of the backwards stepwise Cox regression for in-field recurrence and overall survival

In-field recurrence

Factor

HR (95%CI)

p

Time-interval group

7.7 (1.8–33.8)

0.007

Age

0.96 (0.92–1.00)

0.048

Warm-up time

0.85 (0.72–1.00)

0.047

Overall survival

Time-interval group

2.3 (1.2–4.5)

0.012

T_90,mean

0.57 (0.39–0.87)

0.009

Nodal status

1.8 (0.91–3.4)

0.093