Scottish patients should have a legally binding charter according to independent think tank Reform Scotland.

The organisation has produced a report entitled Patient Power which says the NHS should become more like "insurance-based" health systems in other north European countries. The report argues a constitution would set out the relationship between the health service and patients, and clarify the role of the Scottish Government.

Its author Geoff Mawdsley said on Friday the proposed charter goes further than provisions in the SNP Government's Patients Rights Bill because it defines entitlement to care in the same way as countries such as Sweden and the Netherlands.

Scotland still lags behind other comparable European countries despite a 55% rise in health spending over the past 10 years. According to the report, the "public sector monopoly" enjoyed by the NHS has not provided value for money.

"Insurance-based systems provide clear accountability to patients, while other countries routinely offer patients a greater choice of GP or where they are treated," it says.

Under the recommendations, health boards would be scrapped and replaced with new bodies solely responsible for commissioning treatment from separate providers. Hospitals would be run by independent non-profit making trusts and the overall budget for the NHS would come out of general taxation and be distributed to the new Health Commissioning Co-operatives.

Centrally imposed performance targets for waiting lists and times would also be scrapped - with local NHS managers and clinicians given greater freedom to improve services for patients. "That should give patients a much wider range of choice and should mean we can get rid of performance management through targets and central control," Mr Mawdsley said.

Patients should also be free to take out supplementary insurance for treatment and drugs not provided on the NHS, the report says. It comes after Health Secretary Nicola Sturgeon issued advice last month which would allow patients in some circumstances to pay for new cancer drugs not available on the NHS,  without forefitting NHS treatment.

However, Liberal Democrat health spokesman Ross Finnie MSP claims the report would create a ''two tier system'' that would be  ''ultimately detrimental to patient care.''

"The NHS can always be improved but Liberal Democrats will not support a system that runs contrary to the NHS's founding principle of equal provision for all," he said on Friday.

However, Conservative public health spokesman Jackson Carlaw said "The time has now come for the SNP to stop painting the private sector as a threat to the NHS,"

"People working in the private and independent sectors do a fantastic job and should not have to put up with being depicted as the bogeymen of our NHS for ideological reasons, especially at a time when they are being increasingly called upon to deliver NHS treatments."