As a fellow at the Medical School's Department of Continuing Education 10 years ago, Dr. Timothy Johnson decided that the media coverage of medical news was inadequate.

So he did something about it.

Now on its 10th anniversary, The Harvard Medical School Health Letter, founded by Johnson and Associate Professor of Medicine Stephan E. Goldfinger, reaches more than 315,000 subscribers nationwide, making it the third largest American newsletter.

The eight-page monthly report explains new medical research in lay terms to its mostly middle-aged readers of average income. As the nation's leading vehicle for medical news, The Health Letter details the pertinence of these discoveries to people outside the medical profession.

Although it is non-profit, The Health Letter has a surplus of approximately $750,000 a year which goes to the Medical School, according to Goldfinger.

"There are other fairly decent projects emerging, but our letter is still the best," says Johnson, who appears on World News Tonight, Nightline, and Good Morning America as the ABC News medical editor.

Promoted by Harvard University Press, the medical newsletter was "the first effort by any academic institution to take this approach--to speak about health in an accurate and friendly voice," says Goldfinger, who as chairman oversees The Health Letter.

"We want to give readers enough information that they can participate in making their own decisions about their health care and ask the right questions about it," says Dr. William I. Bennett, the monthly's editor.

"Even though we come at readers with the rather authoritative Harvard name, our aim is to give our readers a sense of power," Bennett says.

The newsletter has spawned imitators at the Mayo Clinic in Rochester, Minn., and the Schools of Public Health at the University of California at Berkeley and Columbia University, according to The Health Letter's general manager, Andrea P. Graham.

"We have a number of imitators, which we consider flattering," she says, "but we don't think the others measure up."

"Compared to other lay-oriented [medical] newsletters, I think it's the best of the bunch," says the monthly's assistant editor, Britain W. Nicholson.

Article ideas come from medical journals and the more than 100 letters that the periodical receives from its readers every month, Bennett says.

A 15-member advisory board, consisting of specialists in all medical fields, reviews every issue of The Health Letter before it is published, Bennett said. Bennett says he, Goldfinger, and Nicholson write many of the articles.

"We have to make sure that our reading level doesn't get too high, but on the other hand, we don't want to patronize our readers," Bennett says