Each year, guns kill an estimated 31,000 Americans and injure another 71,000.

Those numbers alone makes gun violence a major public health issue.

Yet, unlike other public health issues facing the country, such as obesity, heart disease, diabetes, motor vehicle accidents and prescription drug abuse, gun violence is not permitted to be studied by the agency whose mission it is to protect the nation’s health and safety: the U.S. Centers for Disease Control and Prevention (CDC).

Congress cut off CDC funding for such research in 1996, due in large part to an agency-sponsored study on gun homicides that had been published a few years earlier. The study had found that having a gun in the home was associated with an increased risk of homicide by a family member or intimate acquaintance, even after adjusting for factors such as households with illicit-drug users or with people who had criminal records.

In other words, having a gun in your home was much more likely to harm than protect you and your family.

Some politicians — mostly Republicans — were infuriated with the study’s results.

So, instead of allocating more money to figure out ways of preventing those gun-related deaths, they closed down the research completely.

Brilliant.

Needed: good data

Last week, before the tragic shootings in Isla Vista, California, legislation was introduced in Congress that would provide the CDC with $10 million annually to restart its long-dormant research efforts on gun-violence prevention.

“In America, gun violence kills twice as many children as cancer, and yet political grandstanding has halted funding for public health research to understand this crisis,” Sen. Ed Markey (D-Mass), the Senate’s lead sponsor of the bill, said in a statement.

The bill is supported by a long list of organizations, including many that represent physicians, such as the American Medical Association, the American Psychological Association, the American Congress of Obstetricians and Gynecologists, the American Academy of Family Physicians and the American Academy of Pediatrics.

“The dearth of gun violence research has contributed to the lack of meaningful progress in reducing firearm injuries,” the organizations wrote in a letter to Congress last summer.

The organizations also pointed out that the U.S. rate of gun deaths is likely to surpass the country’s rate of motor vehicle accident-related deaths within the next two years. In fact, in some states — Arizona, Colorado, Michigan, Nevada, Pennsylvania and Oregon — it already has.

Why research is essential

Without good research data, we can’t possibly have an informed discussion about what to do about gun violence.

And we no longer have good data, as reporter Lois Beckett discusses in an article published by ProPublica earlier this month. As she explains, we don’t even know for sure the most basic of gun-violence facts, such as how many Americans have been shot over the past 10 years, or if that number has gone up or down during that period.

Writes Beckett:

The government’s own numbers seem to conflict. One source of data on shooting victims suggests that gun-related violence has been declining for years, while another government estimate actually shows an increase in the number of people who have been shot. Each estimate is based on limited, incomplete data. Not even the FBI tracks the total number of nonfatal gunshot wounds.

“We know how many people die, but not how many are injured and survive,” said Dr. Demetrios Demetriades, a Los Angeles trauma surgeon who has been studying nationwide gunshot injury trends.

While the number of gun murders has decreased in recent years, there’s debate over whether this reflects a drop in the total number of shootings, or an improvement in how many lives emergency room doctors can save.

Injuries worsening

One recent study that analyzed data about gunshot-wound patients who were treated at a single Newark, N.J., hospital from 2000 to 2011 found that the overall number of patients injured by guns had remained steady, but that the patients’ wounds were getting more numerous and more serious.

“The percentage of patients who came in with multiple bullet wounds had increased from only 10 percent in 2011 to 23 percent in 2011,” writes Beckett. “The incidence of brain and spinal cord injuries almost doubled.”

In addition, the death rate for gunshot-wound patients actually increased at that Newark hospital during the period studied, from 9 percent to 14 percent.

But, of course, that’s a small single-institution study, and its findings may or may not be reflective of what’s going on across the country.

And that’s why we need a national approach — through the CDC and also, of course, the National Institutes of Health — to tracking and researching firearm violence.

As Beckett notes in her article, a campaign by the National Highway Traffic Safety Administration to gather research on highway vehicle accidents is credited with helping to reduce the number of U.S. deaths from car crashes by more than one-third over the past 20 years.

It’s time — long past time — we had a similar campaign to reduce the number of deaths from guns.

Keeping ourselves in the dark about gun violence will do nothing to reduce those deaths. It will only keep us ignorant.

As Rep. Jack Kingston (R-Ga.), one of the few congressional Republicans who has expressed a willingness to support CDC funding of gun-violence research, told a TV reporter last year: “Let’s let the data lead rather than our political opinions.”

You can read Beckett’s article on ProPublica’s website. It is part of the organizaiton’s ongoing series of articles on guns in the United States.