Under a proposal being discussed at the Imperial College Healthcare Trust in London, doctors would be paid every time a patient survives the operating table or leaves hospital without picking up an infection. Patients groups oppose the proposals, saying it will deter doctors from carrying out complex operations or taking on high-risk patients such as the elderly. The Trust runs five hospitals including Charing Cross, Hammersmith and Queen Charlotte's. It has already started measuring the performance of its doctors ready for the proposal, which could start later this year.