Every household in Scotland should receive information on plans for a single electronic record for NHS patients, according to a watchdog.
Patients' health records will be available on one database
Health Minister Andy Kerr revealed the proposal last month in an effort to improve NHS efficiency and the sharing of patient information.
But a report by the Scottish Consumer Council raised concerns over patient confidentiality.
The Scottish Executive said it planned to use the system by 2007.
The SCC conducted eight focus group discussions across the country, asking people what they thought of the plan to introduce an Emergency Care Summary.
The watchdog said its research suggested strong public support for greater computer-use of sharing health information among medical staff.
But its report, Health Online, said many people were concerned about sensitive information falling into the wrong hands and the planned move had not been publicised enough.
The report says: "To raise public confidence, the NHS needs to raise awareness of what it is doing, the reasons for it, the benefits for patients and the safeguards that are in place to protect patients against breaches of privacy."
The single electronic health record will contain information about current medication and allergies taken from GP records.
The information could then be accessed by medical staff in out-of-hours centres.
According to the SCC, the NHS should ensure personal health information should be protected and keep the public informed before any sensitive medical information is shared.
It also said patients should be able to see what is stored about them and have the chance to correct any factual errors.
SCC chairman Graeme Millar said people should be made aware of their rights.
Mr Millar said technological change had "huge potential" for NHS efficiency and the standard of care available.
But he added: "The idea of sensitive personal information being stored on computers is scary for many of us.
"Our research found that people appreciate the benefits that data sharing can bring but they want to be assured that everything is being done to ensure their personal information is secure.
"Most importantly, they don't feel informed or involved in what is happening.
"The clear message is that the NHS in Scotland needs to pay greater attention to informing and involving members of the public in the move towards a single electronic health record."
A spokesman for the executive said: "Planning work has now begun, with the procurement of the system expected over 2006/07 and deployment over 2007-2010.
"In the meantime, an emergency care summary will be deployed over Scotland by June 2006 for after hours doctors and then to NHS24 and A&E departments.
"This is already up and running in some areas. Out of hours doctors will ask explicitly for consent to access the summary, and if patients object to their information going on to the summary it is withdrawn."
Emergency care summaries are already being used in Grampian, Ayrshire, Arran, the Borders and Glasgow, the spokesman said.
The executive said leaflets and posters were also distributed to each medical practice before the record was introduced in each area.