The figures quoted in this publication are all period life expectancies. Period life expectancies are calculated using age specific mortality rates for a given period, with no allowance for any actual or projected future changes in mortality. This means that period life expectancy at birth for a given time period and area is an estimate of the average number of years a new born baby would survive if he/she experienced the particular area’s age specific mortality rates for that time period throughout his/her life. The figure reflects mortality among those living in the area in each period, rather than mortality among those born in each area. Life expectancy at birth is not the number of years a baby born in the area during the three year period is expected to live (although the term "can expect to live" is used throughout this publication for ease of reading), both because death rates are likely to change in the future and because many of the new borns may live elsewhere for at least some part of their lives.
This publication gives expectation of life at an "exact age". This is the average number of years that those at this age would survive thereafter — if they experienced the particular area’s age specific mortality rates for that time period throughout the remainder of their life. These extracts from period life tables (found in Table 1, Table 2, Table 3, Table 4 and Table 5) are constructed from the estimated population in 2005, 2006 and 2007 and the total number of deaths registered in these years.
The column headed Ix shows the numbers who would survive to the exact age of x, out of 100,000 persons who, from birth, were subject to the mortality probabilities indicated by the death records for 2005-2007. The column headed exo shows the expectation of life — that is, the average number of years of life left to persons aged exactly x who are subject to the 2005-2007 mortality probabilities from age x onwards. For example, 76.7 per cent of the male population and 86.3 per cent of the female population of Large Urban areas could be expected to survive to age 65. A male aged 65 living in a Large Urban area could be expected to live on average another 15.4 years, and a female aged 65 could be expected to live on average another 18.5 years.
Please note that this report uses the 2008 Urban-Rural Classification, whereas the previous report in this series of publications ( Life Expectancy in Special Areas 2004-2006) uses the 2006 Urban Rural Classification.
Comparison of the 2004-2006 life expectancy figures in Urban Rural areas with the 2005-2007 figures is sensible if the objective is, for example, to compare the area classed as Large Urban in the former to the area classed as Large Urban in the latter. If, however, the objective is to compare the area that was classed as Large Urban in the former with the exact same area based on 2005-2007 death records then the life expectancy figures for the period 2005-2007 based on the 2005-2006 Urban Rural classification would be needed — these are available on request.
Further information on the methodology is given in Section 4 of the Life Expectancy for Administrative Areas within Scotland, 2005-2007 publication.