The arc of the country's moral universe is bending toward equality for LGBT people, so the narrative goes. Gay marriage is inevitable. And laws that allow for discrimination on the basis of sexual orientation and identity are the last vestiges of our intolerance.

But publicly funded LGBT research might have a long way to go, according to a study published online today in the American Journal of Public Health.

At the National Institutes of Health, the largest source of funding for medical research in the world, studies focusing on LGBT health are still rare, which "contributes to the perpetuation of health inequities," according to the study. Just one-tenth of one percent of NIH funded studies between 1989 and 2011 focused on LGBT health-related issues. (The number slides up to 0.5 percent if you count HIV/AIDS and research related to sexual health).

And even among the studies that did receive funding, the vast majority focused on sexual minority men (86.1 percent) and HIV/AIDS (79.1 percent).

Only 43 studies — out of 628 total LGBT-health studies — focused on transgender people.

"One of the major findings that surprised me was how great the proportion is related to HIV and sexual health,” says Robert Coulter, the lead author of the study and a Ph.D. student at Pitt's Center for LGBT Health Research, through the Graduate School of Public Health.

"We know that these health disparities exist with regard to tobacco use and homelessness," Coulter says, "so why haven’t intervention studies in these areas been funded yet?”

“It’s because the NIH doesn't care about LGBT health,” says Randall Sell, a public health professor at Drexel University who specializes in LGBT health. "The problem is that NIH is a huge ship and to turn it in another direction is a slow process,” he says.

In the meantime, public health experts worry about a lack of funding for interventions benefiting the LGBT population, whose members have higher rates of mental health disorders, experience more violence and often lack access to quality healthcare (among other problems).

But it isn't entirely clear how much research is going on in the LGBT public health community to start. Coulter's study looked at "keywords" used in research papers. But both Sell and Coulter point out that many papers disguise LGBT research by keeping words like "gay" or "transgender" out of proposals and abstracts. As a result, they say, the study understates the amount of LGBT health research.

"But even if the number doubled," which is unlikely, Coulter says, "there still isn’t enough.”

Still, Coulter hopes the results of the paper will "stir up and incite some more funding" — and the paper lists several recommendations for the NIH, including designating sexual minorities "as priority populations for research" and starting programs to train more LGBT health researchers.

Sell is skeptical that the paper will create dramatic change at the NIH: "If they’re not bothered by it, they’re not going to address it," he says. Still, he adds, "It’s important that an important journal [...] is publishing this.”

UPDATED — the NIH's response to the story:

"The paper can help inform NIH’s efforts to advance the health of lesbian, gay, bisexual, transgender, and intersex (LGBTI) Americans," writes an NIH spokeswoman, who asked not to be named. "In 2011, NIH charged the LGBTI Research Coordinating Committee with gathering input [...] in order to inform the development of a NIH LGBTI Health Research Strategic Plan. Once completed, the strategic plan will address the NIH funding priorities in LGBTI health."

She directed me to a section of the NIH website that reads, "A better understanding of how LGBTI health needs change throughout the lifespan and how they are affected by other factors such as race, ethnicity, and socioeconomic status is also needed," adding that those who want to provide input on the NIH's LGBT research agenda can email: [email protected]