The British Medical Association has published a discussion document assessing the impact of clinical negligence cases on the National Health Service.

"Patient Safety and Clinical Risk" argued that cases should be analysed individually under one of five possible headings: Clinical incompetence, systems failure, cost constraints, patients perceptions of risks, and inherent risks in medical procedures.

If this was adopted "healthcare professionals, managers and governments may be able to define the most effective way of managing risk generally and in relation to individual cases as well as identifying where the responsibility for different levels of risk should lie," says the report.

"While doctors must remain accountable for their own errors they should not have to be responsible for risks over which they have little or no influence," it adds.

Dr Vivienne Nathenson, head of science and ethics at the BMA, argued that a discussion of mistakes in the NHS is overdue.

"It is important to move away from a blame culture where one person takes the blame for mistakes, towards a system where the whole team - doctors, nurses, patients, managers, policy-makers - share the burden of responsibility when things go wrong," she said.

"We're not saying doctors who make mistakes should be let off. However, we need to look at why mistakes happen so we can learn from them and reduce clinical risk to patients."