This dataset is extracted from the HSCNI GPIP (General Practice Intelligence Platform). It is a single integrated view of Northern Ireland GP Practice data held in a central database. This includes all 301 GP Practices who use either EMIS or VISION clinical system across the 17 federations. The data shows the key information about the Dementia diagnosis for each patient. Data is uploaded to a data warehouse periodically in bulk uploads. There are different retention periods for deceased cases based on the system, Vision practices upload a 12 month history of deceased cases while EMIS practices upload a 5 year history. Data outside of these periods is deleted as part of the update process. Data can be accessed for research upon successful completion of an application to the HSC Honest Broker Service, with approval of the HSC Data Access Committee and the GP Editorial Board (NI). Data will be provided in line with the 5 Safes Framework, in anonymised format in the secure computing environment provided by the Honest Broker Service. Remote access is available via the HBS Secure e-Research Platform. The Honest Broker Service application can include additional datasets for linkage (for example prescribing, hospital admission, mortality). For more information about the Honest Broker Service visit: https://bso.hscni.net/directorates/digital/honest-broker-service/