The system could prevent medical mishaps - but potentially breach privacy
The doctors' union claims that England's medical records database is being pushed through too fast, with details sometimes being uploaded without patients' knowledge.
But those behind the new system say many patients are astonished that hospital doctors still do not have access to basic information, and the process to opt out is very straightforward. What are the issues?
What is this database?
The electronic patient care records system will allow an individual's medical records, currently held by GPs, to be accessed by NHS staff across the country.
As well as appointments, it will contain basic information about medication, allergies and adverse reactions to any drugs.
This means that doctors and paramedics will have automatic access to these details, minimising the risks posed by mix-ups and delays. At present some doctors have to wait to find out what prescription medications their patient is taking.
Further details may be added over time but the Department of Health says no sensitive information - such as HIV status for instance - would be added without a discussion between doctor and patient.
Health officials say patients will always have the right to ask a doctor to remove any details, and can review their records at any time.
How far advanced is it?
To date, 1.25m records have gone onto the database, and the process is speeding up.
The plan is to have 50m records in the system by 2014.
But the doctors' union, the British Medical Association, says this is too fast, and that some people are not aware that their records are being uploaded or do not understand how to opt out.
Why is this controversial?
The major criticism is that it risks patient confidentiality.
Doctors and patient groups argue that by putting sensitive details on a national database the information could be abused and even fall into the hands of insurance companies and employers. They question the security of the system, which is part of a £12bn IT upgrade within the NHS.
The flip side is that most agree the system will improve patient care and decrease medical mishaps, if correctly implemented.
How does a patient opt-out?
Before a patient's details go into the database, they will receive a pack containing information about the Summary Care Record. If they decide they do not want to be on the database, the pack contains an order form and pre-paid envelope which they can use to order an opt-out form.
The completed form can then be returned to the patient's GP practice, where forms should also be available.
Alternatively, the form can be ordered by phoning the NHS Care Records service, or downloaded from the website.
The Patients Association wants all patients to be sent an opt-out form as a matter of course.
"The health service should not put in place bureaucratic obstacles to patient choice because they are worried about what patients might choose to do," says its director, Katherine Murphy.
"Many patients are rightly concerned about their confidentiality and consent and if there is even the slightest impression that this is being pushed through it will generate a feeling of mistrust. People who might otherwise have consented could end up opting out which would be the last thing everybody wants."
A spokeswoman for the Department of Health stressed however that much thought had gone into the way in which opt-out forms were provided, and that they wanted to ensure that no-one filled in the document on behalf of another.