Human Life Tables and Survivorship Curves

1. Human Life Tables and Survivorship Curves

2. PURPOSE: Test hypotheses about human survivorship using: Life tables life expectancy Survivorship curves

3. HO: The life expectancy of women is the same as for men or less than that of men. • HA: Women have a greater life expectancy than men. Hypotheses aboutMales and Females BRB R.I.P.

4. Hypotheses aboutMales and Females • HO: Men do not have a greater life expectancy during child bearing years. • HA: Men have a greater life expectancy than women during child bearing years. BRB R.I.P.

5. HO: Human life expectancy has not increased over the period of time during which people were buried in our study area cemeteries. • HA: Human life expectancy has increased over this time period Hypotheses aboutPublic Health BRB R.I.P.

6. What are life tables? • A life table contains age-specific survival and mortality rates in a population. It also contains fecundity and age distribution information. • Life tables come in 2 varieties: • Cohort life table: Follows a group of individuals born at the same time. • Static life table: Constructed by recording the age at death of a large number of individuals. This is what we’ll be making.

7. Life Tables X = a reference number we assigned to refer to the different classes

8. Life Tables X = a reference number we assigned to refer to the different classes

9. Life Tables X = a reference number we assigned to refer to the different classes

10. Life Tables dx= the number of individuals that die in the x age class.

11. Life Tables nx= total number of individuals surviving to the x age class. nx = nx-1- dx-1

12. Life Tables nx= total number of individuals surviving to the x age class. nx = nx-1- dx-1

13. Life Tables (lx) Survivorship: Portion of population that survived to the x age class

14. Life Tables (lx) Survivorship: Portion of population that survived to the x age class

15. Life Tables ax = Given you reach the x age class, what is the probability you live to the NEXTage class.

16. Life Tables ax = Given you reach the x age class, what is the probability you live to the NEXTage class.

17. Life Tables qx = Given you reach the x age class, what is the probability you do NOT live to the NEXTage class.

18. Life Tables ax + qx = 1

19. Life Tables ax + qx = 1 Make three: Males, Females, and Totals for your group’s data

20. Example Life Table

21. How can we test whether health issues influence survivorship, or if there is a difference between males and females? Life Expectancy The amount of time one is expected to live once age class x is reached or during a specified period of time.

22. Use your lab sections’ data: Compute life expectancies for all age groups and for childbearing years.Do this for Males, Females, and Totals Compute life expectancies for the older cemetery and the younger cemetery. You will have 8life ex values

23. Make 2: your data (Male vs. Female) • previous data (Old vs. New) Survivorship curves: BRB R.I.P.

29. How do we know if 2 survivorship curves differ? 1) look at the graphs 2) do a 2test We’ll use Females as our observed group and males plus females/2 as expected. Old vs. new Chi Square tests

30. Graph dx for males vs. females and old vs. new. What does this tell us?

31. A lot of data… To leave today you need 1) Three life tables (male, female, all) using lab section’s data 2) Eight life expectancies 3) Survivorship curve (M andF) (lab section data) 4) Survivorship curve (Old andNew) (Previous Data) 5) dx graphs 6) Two Chi square tests: Old vs. New (Previous data), M vs. F (lab section’s data)