A coalition of more than 100 medical groups is asking Congress to fund research on gun violence at the US Centers for Disease Control and Prevention to end a decades-long drought of federal public health research on the subject.

The groups sent a letter on Wednesday requesting that Congress “end the dramatic chilling effect of the current rider language restricting gun violence research and to fund this critical work”.

The lack of gun violence research at the CDC is attributed to the Dickey amendment, a rider on a 1996 bill which prohibits the organization from using funds to “advocate or promote gun control”. The amendment has been interpreted as a prohibition on almost all gun violence research at the organization, though even its author, former congressman Jay Dickey, has since called on the US to reverse the law and start funding gun research. The groups say that although the language does not expressly prohibit research on gun violence, the amendment combined with the dearth of funding for such research has caused a de facto ban.

The letter was signed by 141 organizations who said they represented more than one million health professionals across the country, including the American Medical Association and the American Association for the Advancement of Science. The groups requested funding for the CDC to be included in health and human services funding for the next fiscal year.

“The medical and public health communities continue to believe gun violence, which claims an average of 91 American lives daily, is a serious public health threat that must be handled with urgency,” said Dr Alice Chen, executive director of Doctors for America, in a statement. “Federal research has addressed many of our Nation’s most pressing public health challenges and it is time do the same with gun violence. Congress must lift the barrier to research that has persisted for nearly 20 years and fund the work that we need to save lives and prevent future tragedies.”

The groups cite several research questions that could be addressed if the CDC were to undertake this research, including how to protect children from gun accidents and how to prevent gun suicides.

Barack Obama instructed the CDC to resume studying gun violence in the wake of the 2012 Newtown school shooting, which claimed the lives of 20 school children and six adults. In 2013, Obama issued a memorandum directing the agency to study “the causes of gun violence and the ways to prevent it”. Obama also requested $10m in 2014 and 2015 to fund the research but both requests were blocked by Congress. The CDC has undertaken only limited research following Obama’s directive, releasing just one study on gun violence last year that took pains to avoid a direct examination of the guns involved.