Life Table Worksheets

Life Table Template V1.2

The download file contains an Excel2000 spreadsheet (there are download files for Excel 97, v5 & v4 as well) that calculates a life table from age-specific death rates. The spreadsheets can be adapted for many life table applications such as cause-deleted life expectancy or health expectancy. These life tables templates represent the actual life tables published in ICES Atlas Report - Adding Years to Life and Life to Years: Life and Health Expectancy in Ontario. (See http://www.ices.on.ca for a copy of this report and source of data). If you have suggestions or comments for future versions contact Doug Manuel (d.manuel@utoronto.ca).

The spreadsheet assumes a previous knowledge of life tables equivalent to that found in an introductory demography textbook/ course (see references for suggested reading). The method used is Chiang's1, adapted for regional/local planning areas2. Chiang's method is used to derive ‘qx’ and ‘Lx’, except for the final age interval. For the interval 90+ years, the method of Hsieh has been used4.

To use this life table for your population you must change the spreadsheet cell values using the following steps. The spreadsheet the columns with light blue shading contain values that should be modified for your population.

1. The most important step is changing the age-specific death rates in cells C31-C50 for females, C5-C24 for males to the age-specific death rates of your male/female population.
2. The table is presently set up for a population similar to Canada, 1990. More accurate life table function estimates can derived by changing the values of ‘ax’, the fraction of interval lived by those in the cohort dying in the interval (Canada 1990 for this life table). The values of ‘ax’ will vary very little between virtually all populations and you should not need to alter them in the spreadsheet. If you are creating a life table for a specific population that has a mortality pattern that is very different from Canada, 1990 then the values of ‘ax’ may need to be changed (possible examples include: developing countries; aboriginal populations; and tables of historic populations). To create new estimates of ‘ax’ see Chiang, 1984.
3. For variance estimates, the actual number of deaths for each age interval ‘Dx’ in your population must be entered in column R. Note that column ‘Dx’ is not the same as column ‘dx’.
4. Health expectancy can be estimated by substituting your age-specific health-related quality of life prevalence estimate into column J. There are a number of health-related quality of life measures that may be used here. We’ve used the age-specific mean Health Utilities Index (HUI). Other possible measures include age-specific disability prevalence to calculate disability-free life expectancy, etc.
5. Cause-deleted life expectancy can be estimated for different diseases by modifying the example of ischemic heart disease eliminated life table. In addition to modifying the all-cause mortality you must also modify the cause-specific mortality ‘Mcx’ in column D. The life table can be further modified to estimate other methods of estimating cause-deleted life expectancy. See Péron and Strohmneger.3

Changes in Version 1.2

• The final age interval is increased from 85+ to 90 + years.
• The method to calculate the final age interval is changed. In Version 1.1, a standard life expectancy estimate 85+ years was used. Version 1.2 used a method of Hseih4 that extrapolates the expected survival from age intervals 80-84 and 85-89 years. The variables a and b are used for these calculations.
• Addition examples and spreadsheets have been added to estimate health expectancy, cause-deleted life expectancy, and cause-deleted health-adjusted life expectancy.
• Addition of a graph for life and health expectancy survival curves.

References

1. Chiang CL. The Life Table and Its Applications. Malabar, Florida: Robert E. Krieger Publ. Co.; 1984.
2. Manuel D, Goel V, Williams J. The derivation of life expectancy at the local level. CDIC 1998;19(2):52-6.
3. Péron Y, Strohmneger C. Demographic and Health Indicators - Presentation and Interpretation. Ottawa: Statistics Canada 82-543E; 1992.
4. Hsieh J. A general theory of life table construction and a precise abridged life table method. Biom J 1991;2:143-62.

Downloads

To download the Life Table Template;

 

 

This page last updated: April 7, 2006