Researchers say that newly unveiled documents reveal that the Food and Drug Administration failed to improve the effectiveness of programs designed to reduce addiction, overdoses, and deaths, despite evidence of deficiencies. The new research, published Monday in JAMA Internal Medicine, shows that the insufficient regulation occurred amid an opioid epidemic that has already cost the lives of more than 400,000 people, while millions more became addicted. In 2011, the FDA started calling on the makers of OxyContin and other addictive opioids to train more than half of an estimated 320,000 doctors on how to safely prescribe the drugs. The goal was to test and track the effectiveness of the training and how it fares in reducing the effects of the epidemic. The FDA, however, never determined whether or not the program—called a risk evaluation and mitigation strategy, or R.E.M.S.—actually worked because the data proved inadequate, according to a review by researchers at the Johns Hopkins Bloomberg School of Public Health.

“What’s surprising here is the design of the program was deficient from the start,” said Caleb Alexander, senior author of the study, adding, “It’s unclear why the FDA didn’t insist upon a more scientifically rigorous evaluation of this safety program.”