Data sources: - all the presentation prescribing data from here - gp to ccg mapping here - old ccg to new ccg code mapping from here - ccg population data from here (2012) - maps Notes: Prescribing data is GP level and there are two types of CCG code (old and new) so this requires 1. obtaining CCG population data 2. obtaining mapping of old to new CCG codes 3. obtaining GP practice to CCG mapping NB: There does not appear to be an authorative list of GP practices. There are other data quality issues that should be written up another time.