About the data
Where the data comes from
The indicators in Longer Lives use records of deaths provided for each year by the Office of National Statistics. For more information about each indicator you can download the data and metadata here.
How the rates are calculated
Premature mortality data throughout Longer Lives is based on directly age-standardised rates. This measure of mortality makes allowances for the fact that death rates are higher in older populations and adjusts for differences in the age make up of different areas, enabling a more accurate comparison between local authorities.
In the calculation of these directly age-standardised rates, the 2013 European Standard Population is used. Further information about this is available from Office for National Statistics.
Two local authorities are not included in Longer Lives – the Isles of Scilly and City of London. The annual number of deaths in these areas are too low to allow for reliable directly age-standardised rates to be calculated for all of the cause groups in Local Lives.. For the same reason, a mortality rate for stroke deaths in Rutland cannot be calculated for 2014-16.
What the colour key indicates
The maps and local authority data pages use a red, orange, yellow and green colour key to indicate how the individual premature mortality rates in local authorities compare. Comparisons are by disease, with the national average, or with local authorities of similar socioeconomic status. Green denotes rates that are statistically significantly better than the average and red denotes rates that are statistically significantly worse. Yellow denotes rates that are within expected limits but better than average, and orange denotes rates within expected limits but worse than average.
In the key, descriptive labels are attached to the colours as follows:
- Red = wor
- Orange = worse than average
- Yellow = better than average
- Green = best
Similar areas comparison
On the map, selecting ‘socioeconomic deprivation’ will divide local authorities into five groups according to their Index of Multiple Deprivation 2015 score. This is illustrated using five different shades of purple. Local authorities can be ordered by socioeconomic group if required.
On the mortality rank tables, these five socioeconomic groups are described as: ‘least deprived’, ‘less deprived’, ‘average’, ‘more deprived’ or ‘most deprived’. This is the basis of the similar group comparison, by which local authorities are allocated to ten groups (rather than five) according to their Index of Multiple Deprivation, allowing their premature mortality rates to be compared with others that have similar levels of deprivation. Currently, only counties and unitary authorities can be compared with similar areas, not county districts.