- Konstantinos Daras
- Benjamin Barr
The SAMHI is a composite annual measure of population mental health for each Lower Super Output Area (LSOA) in England. The SAMHI combines data on mental health from multiple sources (NHS-Mental health-related hospital attendances, Prescribing data – Antidepressants, QOF - depression, and DWP - Incapacity benefit and Employment support allowance for mental illness) into a single index.
Each indicator was individually standardised by rescaling data to have a mean of 0 and a standard deviation of 1 (z-scores). Maximum likelihood factor analysis is used as a method for combining indicators (by finding appropriate weights) into a single score based on the inter-correlations between all the indicators.
Jul 2022 - Change of Factor Analysis approach: 2 factors have been used in the Factor analysis to balance the weights of each indicator. Previous SAMHI (v3.01) has been developed using a single factor where the Prescribing data – Antidepressants and QOF – depression indicators received a higher weighting in the index (~0.8) .
Missing values of Antidepressant Prescribing data in 2011-2013 (for about 1,172 LSOAs) have been updated.