WASHINGTON — Doctors and patients may soon find it easier to learn if clinical trials of treatments worked or not, as the government proposed new rules Wednesday expanding what researchers are required to publicly report.

Thousands of Americans participate in clinical trials every year, to test new treatments or diagnostics, compare which older therapies work best, or help uncover general knowledge about health.

Many of the studies are reported in scientific journals or trumpeted in the news. But researchers don’t always publicly reveal their results, especially when the findings show a treatment doesn’t work as initially hoped, said Dr. Francis Collins, director of the National Institutes of Health.

Collins cited one recent analysis that found less than half of studies had been published in a peer-reviewed scientific journal within 30 months of completion.

“This is simply not acceptable,” Collins said. “This dissemination of trial results is the way in which medical progress occurs.”

Wednesday’s proposals aim to change that by increasing information available on a public database – www.clinicaltrials.gov – that already is a source for patients and doctors seeking to find the latest studies that need volunteers.

Under the new proposals, all clinical trials that receive funding from the NIH would have to start listing a summary of the study results within a year of completion. So would certain other studies, under an expansion of Food and Drug Administration rules that could require compliance even if they involve products not approved for sale.