At the moment Hospital administration and GP Surgeries operate independently from area to area and from different systems, if you move from one area to another it takes up to 6 months for you to be able to access your medical records online.
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If you are undergoing investigations in one hospital and move to another area your new hospital does not have access to what or how far your last hospital was with your investigations and the same with your new GP Surgery if the country had a National NHS Database Centre with all patients being issued with an NHS Chipped card they could use that card in any hospital or GP to access their medical records and on going treatment with a chipped card this would prevent identity fraud and ease admin.