Practical Solutions Survival Analysis Practical Solutions 2 The

Practical Solutions Survival Analysis

Practical Solutions 2. The life table for Group B should look like this: Interval Entering Withdrew At risk Events Failing Surviving Cum. Survival 0 to <10 8 1 7. 5 2 0. 267 0. 733 10 to <20 5 4 0. 8 0. 2 0. 147 20 to <30 1 1 1. 0 0 0 2

Practical Solutions: Instructions 3. To produce the Life table you will need syntax similar to the following: * Producing the Life table. SURVIVAL TABLE=time BY ln_yesno(0 1) /INTERVAL=THRU 144 BY 12 /STATUS=status(1) /PRINT=TABLE. 3

Practical Solutions: Output 4

Practical Solutions: Output 5

Practical Solutions: Instructions 4. To produce a Kaplan-Meier curve and the log-rank test you will need syntax similar to the following (You will then need to customise the plot itself with the graph editor afterwards): * Producing the KM plot. KM time BY ln_yesno /STATUS=status(1) /PRINT TABLE MEAN /PLOT SURVIVAL /TEST LOGRANK /COMPARE OVERALL POOLED. There is clearly a significant difference between the two categories, with survival being better in the group without lymph node involvement (p<0. 001). 6

Practical Solutions: Output 7

Practical Solutions: Output It can be seen that the mean survival times are: • 124. 92 (95% CI: 122. 18 to 127. 66) months for no involvement, • 111. 33 (95% CI: 105. 44 to 117. 23) months for nodal involvement. There are no median survival estimates as at no point over the duration do 50% of the subjects in either group experience an event. 8

Survival Analysis: An Introductory Course Session Questions and Answers

Session Questions & Answers For the Breast cancer dataset: 1. In the group of women with no lymph node involvement how many died in the 4 th year of observation? A) 11 2. In the group of women with lymph node involvement what proportion were still alive after 5 years of observation? A) 0. 8414 10

Session Questions & Answers For the Breast cancer dataset: 3. Was there a significant difference in survival for the two groups (with and without lymph node involvement)? What was the pvalue from the log-rank test and which group had better survival? A) Yes, p<0. 001, Lymph nodes unaffected 4. In the group of women with lymph node involvement what proportion were still alive after 5 years of observation? A) From the plot it is just below 0. 85 From the table it is 0. 8398 11