Independent life expectancy in New Zealand, 1996-97.

The objective of this article is to describe independent life expectancy (ILE) in New Zealand in 1996-97, including variations in this indicator between age, gender and ethnic groups. ILE is defined as the number of years a person can expect to live without any self-reported functional limitation requiring the assistance of another person or a complex assistive device. ILE is a positive measure of health. Its complement, expectation of life with dependency (LED), is also a useful indicator. Together, ILE and LED add up to total life expectancy (LE). The contribution to ILE from disability and mortality at each age is analysed in this article. The elasticity of ILE to changes in mortality and to changes in disability is also investigated. Finally, the burden of injury is estimated by calculating the potential gain in ILE that would result were injury-related disability and mortality to be eliminated.