NHS Oxfordshire medical records to be shared online
The medical records of people in Oxfordshire will be put online and made accessible to doctors around England.
About 557,000 people registered with GPs will receive letters about the changes from Tuesday, with the choice to opt out.
Oxfordshire Primary Care Trust said the £500,000 roll-out would benefit patients who became ill away from home.
Katherine Murphy, chief executive of the Patients Association, said patient confidentiality should be ensured.
Patients should understand that their records may be used by multiple professionals and agencies and they must be kept updated on any change to the records, Ms Murphy said.
Andrew Fenton, chief information officer at NHS Buckinghamshire and Oxfordshire Cluster, said: "We've found that many people are keen to have information safely and securely shared and only viewed by professional health clinicians.
"The NHS network is a secure network."
The NHS Care Records Service in Oxfordshire will be part of the national summary care record, which will include information on allergies, medication, and any adverse reactions patients have had to medicines.
The local Oxfordshire care summary will also provide more detailed information and be made available to local healthcare professionals.
Dr Andy Chivers, clinical lead for the Oxfordshire care summary, said it would improve patient care "in more complex cases".