Disentangling rectangularization and life span extension with the moving rectangle method.

Ann Epidemiol 2016 Mar 12;26(3):218-21.e2. Epub 2016 Jan 12.

Section of Gerontology and Geriatrics, Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands; Department of Public Health and Center of Healthy Aging, University of Copenhagen, Copenhagen, Denmark.

Purpose: The moving rectangle method is used to disentangle the contributions of rectangularization and life span extension to the increase in life expectancy. It requires the choice of an endpoint of the survival curve that approaches the maximum age at death. We examined the effect of choosing different end points on the outcomes of this method.

Methods: For five developed countries, survival curves from age 50 years were constructed per calendar year from 1922 onward. Survival values of 0.1, 0.01, and 0.001 were chosen as end points of the survival curve, and the contributions of rectangularization and life span extension to the increase in life expectancy were calculated using the moving rectangle method.

Results: The choice of different survival values as end points profoundly influenced the estimated contributions of rectangularization and life span extension to the increase in life expectancy. When choosing 0.001, rectangularization contributed most years, whereas when choosing 0.1, life span extension contributed most years.

Conclusions: When the moving rectangle method is used to estimate the contributions of rectangularization and life span extension to the increase in life expectancy, its outcomes depend on the choice of the endpoint of the survival curve.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.annepidem.2015.12.010DOI Listing
March 2016
14 Reads

Publication Analysis

Top Keywords

span extension
24
life span
24
rectangularization life
20
increase life
16
extension increase
16
contributions rectangularization
16
life expectancy
16
moving rectangle
16
rectangle method
12
survival curve
12
life
10
choice endpoint
8
endpoint survival
8
survival values
8
survival
6
span
6
extension
6
rectangularization
5
expectancy calculated
4
curve contributions
4

Similar Publications