Trends in disability-free life expectancy.
OBJECTIVE
To assess trends in Disability-Free Life Expectancy, in life expectancy with disabilities according to levels of severity and in Disability-Adjusted Life Expectancy in the Netherlands between 1989 and 2000.


METHODS
The disability-free life expectancy, a composite population health status measure, was calculated with data on long-term disability. Weights reflecting the impact of disability on personal functioning were assigned to different levels of severity of disability, in order to calculate a Disability-Adjusted Life Expectancy and to define cut-off points, in order to distinguish between levels of severity.


RESULTS
At an aggregated level, for both males and females at the ages of 16 and of 65 years, an increase in years with disabilities and a decline in disability-free life expectancy were observed. These trends were mainly caused by a rise in the number of years with mild disabilities, with the number of years with moderate and severe disabilities decreasing. The combined changes have resulted in an increase in the Disability-Adjusted Life Expectancy.


CONCLUSIONS
Trends in disability-free life expectancy and in years with disabilities provide support for a scenario of dynamic equilibrium. The number of years with moderate and severe disabilities has reduced, resulting in an increase in the number of years with minor disabilities. Further research should focus on the underlying causes of the increase of years with minor disabilities.
Perenboom
R J M
RJ
TNO Prevention and Health, Leiden, The Netherlands. rjm.perenboom@pg.tno.nl
Van Herten
L M
LM
Boshuizen
H C
HC
Van Den Bos
G A M
GA
D000293:Adolescent; D000368:Aged; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008017:Life Expectancy / Q000639:trends*; D008297:Male; D009426:Netherlands