WASHINGTON, D.C. ? Government investigators have found that drug makers are failing to file status reports that show progress they have made in conducting safety studies.

According to a review by the inspector general for the Health and Human Services Department, 35 percent of status reports that drug makers were supposed to file in fiscal year 2004 were missing entirely or contained no information on agreed-to studies.

Investigators said that even completed status reports often lacked information that would be useful in monitoring the progress of studies.

Such studies are considered important because they can shed light on the safety and effective use of drugs. The FDA requires all new drugs to undergo clinical testing, but trials often involve relatively small numbers of people, so the FDA frequently ask drug makers to conduct postmarketing studies.