People can opt out of the system

Millions of patient records are to go online in London after long delays to an NHS IT upgrade in the city.

The £12bn government programme has been beset with problems and is four years behind schedule.

The records, which contain details of patient medications and allergies, will go live on Thursday following pilot studies across England.

It is hoped the system will allow data to be shared more easily. The scheme will also be rolled out across England.

The summary care record is designed to securely hold details of medications, allergies, adverse reactions and other key health information.

It is based on a patient’s GP record but is designed so any doctor treating a patient can add to it.

Read more about London Medical records going on line