You are reviewing the survival statistics from your hospital using a new treatment (Treatment A) compared to the old treatment (Treatment B) for breast cancer. The following table lists the number of survivors after each year of treatment for both treatments A and B. Answer the following questions using the table. Assume no patients were lost to follow-up.
• Calculate the survival rates for treatments A and B for each year after treatment: P1, P2, P3, P4, and P5. • Calculate the probability of surviving for 1, 2, 3, 4, and 5 years cumulatively for each of the treatments. • Your administrator would like to know how the treatments compare to each other. You are asked for the following information: − What is the likelihood of surviving 5 years if you made it to 4 years of treatment for each of the treatments? − How does treatment A compare to treatment B for each year of survival after treatment? − Which treatment has the best 5-year survival rate? • Plot the survival curve for both treatments on the same graph. • Why might there be differences between these two treatments? • What are some potential confounders that may contribute to one treatment working better than the other? • Explain the advantages and disadvantages of screening tests. • What are the limitations to performing survival analysis? • How might patients lost to follow-up affect the validity of survival analysis? • What are the differences between the actuarial method of survival analysis and the Kaplan–Meier method?