It is not clear whether a seven-fold rise in NHS clinical negligence costs since 1995-96 is due to incompetence in the health service or to wider factors, NHS chief executive Nigel Crisp told the public accounts committee last week. But research being undertaken for the Department of Health should help reveal the causes of increased liability, he said. The committee, which was examining the rising costs of negligence claims, also heard from NHS Litigation Authority chief executive Stephen Walker that patients were being compensated as quickly as possible. He said that as the level of damages increased, delays cost the NHS money.