Pilot schemes for the delayed and controversial NHS programme to share data from patients’ medical records might not start until well into the new year, it has emerged.

The launch of the care.data programme was postponed for at least six months in February this year – well past its planned date of April 2014 – and NHS has now said it will not even have completed signing up GP practices for experiments in how it might work until the new year.

Doctors in four parts of the country will be involved, and there will be trials in how to inform the public and patients about how the system will work, its perceived benefits and on how they can opt out of having confidential information shared.

It was unclear last night how far the so-called pathfinder process will have got before the May election. Earlier this year, Labour called the delay “a shambles of the government’s own making”.

The continuing lack of a firm date to start or even a new public awareness campaign came as the All Party Parliamentary Group for Patient and Public involvement in Health and Social Care and the Patients Association, which acts as its secretariat, published a report raising continuing concerns. Issues that needed to be resolved included the so-far inadequate consultation of the public, clarification on what data could be collected and penalties for those who misused or abused patient information, they said.

Under the pathfinder schemes, involving three NHS clinical commissioning groups in Leeds and those for Somerset, West Hampshire and Blackburn with Darwen, coded medical details held by GPs will be brought together with hospital data at the Health and Social Care Information Centre (HSCIC).

NHS England insists care.data will eventually create a national picture of health patterns so commissioners can study issues such as diagnoses, waiting times and patterns of illness or disease but concerns have remained over just what access to the data commercial firms might have.

The delays announced in February came after 26m households in England were sent leaflets about the plan but polls suggested two-thirds of people had not seen them.

Katherine Murphy, chief executive of the Patients Association, said of its report: “Evidence taken from a cross-section of healthcare charities, royal colleges, the research community and NHS England, all points towards strong support for medical data sharing in theory. Patients and the public are broadly supportive of the principle of using health data that is in the public interest.

“However, many people still have deep concerns about the programme and are worried about how their data will be used.”

Eve Roodhouse, NHS England’s programme director, said:“We’re very pleased patient groups and charities support the care.data programme, which will help us join up health information between GPs and hospitals. We know we have more to do to communicate with the public about the programme and are fully committed to addressing the concerns raised, which is why we have established the pathfinder stage.”