Deprivation has been defined using the English Indices of Deprivation, commonly known as the Index of Multiple Deprivation (IMD). This is the official measure of relative deprivation for Lower Super Output Areas (LSOAs) in England and ranks every LSOA in England from 1 (most deprived area) to 32,844 (least deprived area). Deprivation deciles are calculated by ranking the 32,844 neighbourhoods in England from most deprived to least deprived and dividing them into 10 equal groups. These range from the most deprived 10% of neighbourhoods nationally to the least deprived 10% of neighbourhoods nationally.
For further information see: https://www.gov.uk/government/statistics/english-indices-of-deprivation-2019
For NCMP, we provide deprivation data based on both where the child lives and where the child attends school. Deprivation based on where the child lives is more accurate since sometimes children attend schools in areas with different relative deprivation compared to where they live. Consequently, this report uses the deprivation decile of the child postcode to define deprivation for the current year. However, there were issues with the quality and completeness of the child postcode in the early years of NCMP and therefore, for time series comparisons, the deprivation decile for the school postcode has been used.