When U.S. health regulators find serious problems with how medical researchers collect their data, the researchers' final reports often don't mention it, a new analysis suggests. Out of 78 published papers reporting on clinical trials in which the U.S. Food and Drug Administration found very serious issues, only three mentioned any violations, the new report says. These are major things," said Charles Seife, a journalism professor and the study's author. Using documents and data from 1998 to 2013, Seife and his students at New York University in New York City identified 57 clinical trials that received an "official action indicated" violation - the most serious type of violation for trials - for reasons including poor record keeping, false information and poor patient safety. The problems that weren't reported were sometimes egregious. One paper, for example, said all patients reported improvement, but in fact, the FDA found that one patient had a foot amputated two weeks after receiving the treatment. In another case, the entire clinical trial was considered unreliable by the FDA - but the published paper didn't mention that. In another, researchers falsified data, which led to one patient's death. Data on these violations are not readily available. So it's impossible to say how often tainted data are published and how often the violations are noted, Seife said.