The US drug industry has persuaded key Congressional legislators to water down proposed legislation that would require detailed public disclosure of payments and gifts to doctors.

In September 2007 the senators Chuck Grassley and Herb Kohl introduced the Physician Payments Sunshine Act 2007 to counter an estimated $19bn (£9.6bn; €12.3bn) spent a year courting doctors. At the time Mr Grassley told the Senate that “the best disinfectant” to payments to doctors was “sunshine,” which means openness.

Benefits provided to doctors, he said, “can be a simple dinner after work, or they can add …