Life_table_notation

Life_table_notation - This work is licensed under a...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
Copyright 2008, The Johns Hopkins University Marie Diener-West, and Sukon Kanchanaraksa. All rights reserved. Use of these materials permitted only in accordance with license rights granted. Materials provided “AS IS”; no representations or warranties provided. User assumes all responsibility for use, and all liability related thereto, and must independently review all materials for accuracy and efficacy. May contain materials owned by others. User is responsible for obtaining permissions for use from third parties as needed. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike License . Your use of this material constitutes acceptance of that license and the conditions of use of materials on this site.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Life Tables Marie Diener-West, PhD Sukon Kanchanaraksa, PhD
Background image of page 2
Section A Clinical Life Tables, Part 1
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 Clinical Life Table ± A fundamental technique of survival analysis that deals with “time to event” A basic example is “time to death” ± It can answer the question of the chance of survival after being diagnosed with the disease or after beginning the treatment ± The event can be any other health event—not just death It can be relapse, receiving organ transplant, pregnancy (in a study of infertility), failure of treatment, recovery, etc. ± It handles variable time of entry and (variable time of) withdrawal of individuals from the population ± It calculates cumulative event-free probabilities and generates a survival curve
Background image of page 4
5 Time since beginning of follow-up (Year) Number at beginning Deaths 1 200 20 2 30 3 40 Example ± A group of 200 subjects were followed for three years ± Deaths (events) occurred throughout the three years ± What is the chance of surviving at the end of the three years?
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
6 Following a Population Patient Begin follow-up Death 1995 2000 Year Year since follow-up 1 2 3 0
Background image of page 6
7 Clinical Life Table Notation ± = number alive at the beginning of time t ± = number of deaths during the time interval l t d t
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
8 Apply Notation ± Apply notation to the table in the example Time since beginning of follow-up (Year) Number at beginning l t Deaths d t 1 200 20 2 30 3 40
Background image of page 8
9 Fill in the “Number at Beginning” Column ± Fill in the missing cells Time since beginning of follow-up (Year) Number at beginning l t Deaths d t 1 200 20 2 30 3 40 200–20 = 180 200–20 = 180 180 180–30 = 150 180–30 = 150 150
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
10 l t d t Clinical Life Table Notation ± = number alive at the beginning of time t ± = number of deaths during the time interval ± = probability of dying during the time interval ± = probability of surviving in the time interval q t = d t /l t p t = 1 q t
Background image of page 10
11 Interval l t d t q t p t 1 200 20 2 180 30 3 150 40 20/200 = 0.1 20/200 = 0.1 0.1 1.0–0.1 = 0.9 1.0–0.1 = 0.9 0.9 30/180 = 0.17 30/180 = 0.17 0.17 1.0–0.17 = 0.83 1.0–0.17 = 0.83 0.83 Calculate Probabilities of Dying (q) and Surviving (p) 0.27 0.73
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/04/2011 for the course PB HLTH 140 taught by Professor Tarter during the Fall '10 term at Berkeley.

Page1 / 40

Life_table_notation - This work is licensed under a...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online