The first live pilot of the electronic patient record system at the heart of the £12bn National Programme for NHS IT will start in early May.

More than 14,000 patients at two GP practices in Bolton are being contacted today about the plan and will have two months to opt out of the system if they want.

Name and address information is already held on the national data 'spine'. The next stage is to create a summary care record which holds information on the patient's allergies, adverse reactions and current medication.

From May all Bolton patients who do not opt out will have their data uploaded to the spine, which will then be accessible by relevant clinicians in the Primary Care Trust's casualty departments, out-of-hours GP services and ambulance staff.

The Bolton pilot is the first of seven expected to go live this year, prior to full roll out of the system from 2008.