174 CHAPTER 10 Survival Analysis
Males: 1, 3, 4 + , 9, 11, 15
Females 1, 3 + , 6, 9, 10, 11 +(a) Calculate the Kaplan – Meier curve for males
(b) Calculate the Kaplan – Meier curve for females
(c) Test for a difference between the male and female survival curves
using the chi - square test.
(d) Compute the logrank statistic and perform the same test as in c using
this statistic? Do you reach the same conclusion as in c? Are the
chi - square and logrank test statistics close in value? Are the p - values
nearly the same?- What assumptions are required for the Cox proportional hazard model?
Why is it called a semi - parametric method? - Suppose a cure model is known to have S 1 ( t ) = exp( − 0.5 t ).
Recall S ( t ) = p + ( 1 − p ) S 1 ( t ). Suppose that we know that S (2) = 0.5259.
Can you calculate the cure rate for this model? If so what is it?