FDA defends its reduction of warning letters. Source: ACC TV

The number of warning letters issued by the FDA has dropped by half in the past 10 years, which could indicate a change in enforcement tactics in an agency facing criticism about its policing of the food and drug industries.

In 2002, the FDA changed its policies and required that all warning letters go through the agency's chief counsel's office, which the agency said was designed to strengthen the letters and make them legally consistent and credible, according to the Wall Street Journal(WSJ).

In 2001, the agency issued 1,032 warning letters, the WSJ reported. In 2006,  the number of letters dropped to 538, and 471  in 2007.

Some members of Congress, FDA staffers and former agency officials criticized the change, suggesting it favored industry, the WSJ said.

Dan Troy, former FDA general counsel and author of the policy change, told the WSJ that the legal review process was aimed at countering industry sentiment that the FDA did not always follow through on the warnings.

FDA Commissioner Andrew von Eschenbach acknowledged the drop in the number of warning letters, but said the agency sends them now for more serious deviations, according to the WSJ.

David Elder, director of the FDA's office of enforcement, also warned against measuring the agency's enforcement success by counting warning letters, the WSJ reported.

"Numbers of warning letters are just conveniently easy to measure,” Elder said. Measuring the agency's efforts to protect public health "is a much more complicated analysis," he said.

The WSJ said that the decline in warning letters came as the FDA also changed its enforcement approach. Rather than sending out individual warning letters to separate companies for similar violations, the FDA alerts the industry via press releases and other forms of communication when it notices problems, Elder said.