# Biostats spss kaplan-meier curve | Computer Science homework help

Due 4/20/19 11p.m EST

Be on time and ORIGINAL WORK!

Don’t ask if you haven’t read directions!

DATA ATTACHED ALONG WITH STEP BY STEP GUIDE!

The Kaplan-Meier curve is a way to evaluate longitudinal data and estimate conditional survival rates through the illustration of a series of conditional probabilities.

For this Assignment, you use the Kaplan-Meier method to evaluate time-to-event data collected through a longitudinal study described in the Week 8 Dataset (SPSS document). You also create a survival curve and estimate survival distributions.

The Assignment

Using Wk 8 Dataset (SPSS document)

1. Data
1. 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”.
2. Produce the appropriate descriptive statistics, numerical and graphical, for the following variables:
• Event
• Interval
• Tx
• Num
• Size
• Time
2. Kaplan-Meier Survival Analysis (Without factor or Strata)
1. 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.
2. Produce a Survival Table (you do not need to submit this)
3. Produce a plot of the survival function
4. 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?
3. Kaplan-Meier Survival Analysis (With Factor)
1. 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.
2. Test the difference between Tx groups (Compare Factor) using Log-Rank, Breslow, and Tarone-Ware
3. Produce a plot of the survival function
4. Describe what the Overall Comparisons mean in terms of treatment groups and survival times.
5. 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?