Lecture 3 - Life Table Analysis

Question 1

What does a life table analysis measure?

Answer 1

Survival time:

• time to an event
• event may or may not be fatal

Question 2

What is a “censored case” ?

Answer 2

true survival is unknown

Question 3

What measures are irrelevant in a life table analysis ?

Answer 3

mean and SD

Question 4

Kaplan-Meier Curve:

What is Step 1?

Answer 4

Order survival times both censored and uncensored in order from smallest to largest

*If a censored number has the same value as an uncensored number, the uncensored appears 1st

Question 5

Kaplan-Meier Curve:

What is step 2?

Answer 5

In second column rank from 1 to n

Question 6

Kaplan-Meier Curve:

What is step 3?

Answer 6

Make a 3rd column and label it r:

-Same as 2nd but only for uncensored observations

Question 7

Kaplan-Meier Curve:

What is step 4?

Answer 7

(n - r) / (n - r + 1)

Question 8

Kaplan-Meier Curve:

What is step 5?

Answer 8

• To obtain survival rate at time t
• Multiply all values in column 4 up to and including t
• If some uncensored values are ties the smallest rate is the answer

Question 9

Some Kaplan-Meier Curves have tick marks on them. What do they represent?

Answer 9

the time that the patient was censored out

Question 10

In the actuarial method, we classify observations into time ______

Answer 10

intervals

Question 11

How do you calculate n* (no at risk at start) ?

Answer 11

n* = n - (c/2)

Question 12

How do you calculate q (interval death rate) ?

Answer 12

q = d/n*

Question 13

How do you calculate p ?

Answer 13

p = 1-q