The Life Expectancy and Health of the Population Indicators published by Idescat are the life table, the life expectancy and the standardised mortality rate.
The life table is the universally accepted demographic model for structurally and completely describing a population's experience of mortality and providing comparative measures for life expectancy. The model used to construct the life table assumes that an initial cohort of 100,000 live births is subject to the same sex and age specific death rates experienced by a real population during a specific period of time. The life tables using five-year data, in which reference year of the table corresponds to the middle year of the period. So, 1983, first year in the series, is the reference year of the data for the 1981–1985 period.
Life expectancy at birth is interpreted as the number of years that, on average, a generation of live births can expect to live if the mortality conditions do not vary in the future. Life expectancy at 65 years is an estimation of the average number of years that the population of this age can expect to live if the mortality conditions for the specified year or period remain constant.
The standardised mortality rate (SMR) by age is the number of deaths (expressed per 100,000 inhabitants) that occur within a given territory according to the mortality rate by sex and age of the territory in question and with the age structure of a standard population.
This method, known as direct standardisation, calculates the rate as the weighted average of mortality rates by age group, where the weighting factors are a standard reference population.