Reviews/Analyses

Measurement and utilization of healthy life expectancy: conceptual issues J.-M. Robine,l J.-P. Michel,2 & L.G. Branch3 The periodic calculation of healthy life expectancies permits the evaluation of the impact of new health policies at a given moment, as well as the assessment of trends under changing health conditions. In spite of their apparent simplicity, the results obtained will have to be interpreted by experts. Useful ref-erence values can be provided by international comparisons. However, several choices remain to be made, such as (i) the types of morbidity and disability data to be associated with mortality data; (ii) the multiple indicators available; (iii) the type of observations to be recorded, i.e., "abilities " or 'perform-ances"; (iv) whether or not the recovery of lost functions should be considered; (v) the mode of compu-tation, i.e., life expectancy before the first morbid event or global healthy life expectancy; and (vi) the determination of thresholds based on either relative or absolute criteria. Determining population health status Numerous attributes have been attached to the measurement of healthy life expectancy (1). But in the absence of a clear distinction between the health status of individuals and that of populations, two questions arise that are connected and often con-fused with one another: (1) By living to a greater age, are we not individual-ly becoming more and more weak and decrepit? (2) As more people survive at every age level, are we not collectively becoming less strong and less effective at each increasing age? Any calculation of healthy life expectancy must take into account the health status of the population and determine whether this improves over a period of time. A calculation of cross-sectional healthy life expectancy answers the first question given abov