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. 2010 Oct 18;28(34):5061–5066. doi: 10.1200/JCO.2010.29.1351

Table 4.

Multivariate Cox Proportional Hazards Model of Overall Survival

Variable HR 95% CI P*
RX duration, days
    ≤ 53 1.00
    > 53 1.09 0.84 to 1.40 .5219
Age, continuous 1.03 1.02 to 1.04 < .0001
Sex
    Female 1.00
    Male 1.79 1.42 to 2.26 < .0001
KPS
    90, 100 1.00
    60,70,80 1.67 1.29 to 2.17 < .0001
T stage
    T1/T2 1.00
    T3/T4 1.49 1.18 to 1.87 .0007
N stage
    N0 1.00
    NX/N1/N2/N3 1.90 1.47 to 2.46 < .0001
Total primary central axis dose (Gy), continuous 0.97 0.96 to 0.99 .001

Abbreviations: HR, hazard ratio; RX, overall treatment; KPS, Karnofsky performance score.

*

P value from χ2 test using the Cox proportional hazards model.

Interpretation: An increase in dose of 1 Gy means a decrease in the hazard of death by 3%; an increase in dose of 5 Gy means a decrease in the hazard of death by 13%; an increase in dose of 10 Gy means a decrease in the hazard of death by 24%.