The letters come two months after the editors of The New England Journal of Medicine published their first "expression of concern" about the November 2000 article, sharply criticizing Merck — and, implicitly, the outside scientists who were co-authors — for failing to present a complete picture of Vioxx's heart risks.

In their letter yesterday, the outside scientists strongly disagreed. They said that the journal's concerns were misguided and that the article in 2000 had adequately disclosed Vioxx's risks. "Our original article followed appropriate clinical trial principles and does not require a correction," the scientists wrote.