kaplan-meier survival curve
The Assignment
Using Week 8 Dataset (SPSS document) from the Learning Resources area, answer the following:
- Data
- Create a variable for Time-to-event by subtracting the start time (variable = start) from the stop time (variable = stop). Label the new variable “Time”.
- Produce the appropriate descriptive statistics, numerical and graphical, for the following variables:
- Event
- Interval
- Tx
- Num
- Size
- Time
- Kaplan-Meier Survival Analysis (Without factor or Strata)
- Run a Kaplan-Meier analysis in SPSS, using Time as the Time variable and Event as the Status variable (Be sure to define the event). Do not add a factor or strata at this time.
- Produce a Survival Table (you do not need to submit this)
- Produce a plot of the survival function
- What is the mean survival time (include confidence intervals)? What is the median survival time (include confidence intervals)? Why do you think they are so different from each other?
- Kaplan-Meier Survival Analysis (With Factor)
- Run a Kaplan-Meier analysis in SPSS, using Time as the Time variable and Event as the Status variable (Be sure to define the event). Add Tx as the factor.
- Test the difference between Tx groups (Compare Factor) using Log-Rank, Breslow, and Tarone-Ware
- Produce a plot of the survival function
- Describe what the Overall Comparisons mean in terms of treatment groups and survival times.
- Kaplan-Meier Survival Analysis (With Strata)
- Run a Kaplan-Meier analysis in SPSS, using Time as the Time variable and Event as the Status variable (Be sure to define the event). Add Interval as the Strata variable.
- Produce a plot of the survival function for each strata.
- Why would you want to produce Kaplan-Meier Survival Curves after stratifying for a variable?
Resources: Daniel, WW & Cross, CL. (2013). Biostatistics: A Foundation for Analysis in the Health Sciences. Hoboken, NJ: Wiley.
- Chapter 14: Survival Analysis (pp. 750-767
