please help

You should now be uble to uttempt the following past exam questions on Cox regression. Question 9.16 Subject 104, September 2004, Question 3 A study hus been underraken into the effect of a new treatment on the sarvival times of patients suffering from a tropical diserse. The following model has been fitted: where h(f) is the hazard at time t, where r is the time since treatment haiflis the toaseline hazard at time f is a vector of covariates, where 4. = period from diagnosis to treatment in years 2. =0 if existing treatment given, 1 if new treatment given 33=0 if fentule, 1 if male is a vector of parameters, where =0.5 (i) State the group of lives to which the baseline hazard applies - [1] (ii) For a male who was given the new treatment 6 months affer dingenosis: (ii) Write down the hazzan function, in termas of h0(t) anly. (b) Express the survivul function, in terms of h0(t) only. (iii) For a fermule given the new treatment at the time of diagnogis, the probability of survival for 5 years is 0.75. Calculate the probability that the male in (ii) will survive 5 years. [Total 7] You should now be uble to uttempt the following past exam questions on Cox regression. Question 9.16 Subject 104, September 2004, Question 3 A study hus been underraken into the effect of a new treatment on the sarvival times of patients suffering from a tropical diserse. The following model has been fitted: where h(f) is the hazard at time t, where r is the time since treatment haiflis the toaseline hazard at time f is a vector of covariates, where 4. = period from diagnosis to treatment in years 2. =0 if existing treatment given, 1 if new treatment given 33=0 if fentule, 1 if male is a vector of parameters, where =0.5 (i) State the group of lives to which the baseline hazard applies - [1] (ii) For a male who was given the new treatment 6 months affer dingenosis: (ii) Write down the hazzan function, in termas of h0(t) anly. (b) Express the survivul function, in terms of h0(t) only. (iii) For a fermule given the new treatment at the time of diagnogis, the probability of survival for 5 years is 0.75. Calculate the probability that the male in (ii) will survive 5 years. [Total 7]