HIV-infected men in South Africa are nearly one-third more like to die than women, even though both receive similar treatment. But researchers say they don’t know why.

University of Cape Town’s Morna Cornell led a team of researchers who looked at more than 46,000 adults taking antitrovirals drugs between 2002 and 2009.

“Why we started looking at this was because increasing numbers of studies are coming out, which are reporting that men have a higher risk of death on antiretrovirals than women. And obviously this is an issue of great concern and something we wanted to understand a bit more,” she said.

Studies show that, in fact, men are one-third more likely to die than women during treatment. But Cornell said too often researchers may simply assume they know why, when in fact they do not.

“These papers are published. They find higher mortality, but that they conclude that this is largely due to individual-level factors. They argue that it's because men come in later for treatment. It’s because men are less likely to be adherent to their treatment. They are suggesting maybe men are more likely to be lost to follow-up from a program and then to die. Maybe they’ve got different virologic responses or they’re not taking the treatment properly, et cetera,” she said.

Cornell said she wanted to study in a “very systematic way” all the possible explanations as to why men have a much greater risk of death.

“The first thing that we did is that we looked at the differences when people enroll. We then said, ok, well, that explains some of it, but it doesn’t explain all of it. We’ve still got this 30 percent difference. Well, could it be because, as many people have suggested, men are more likely to be lost to a program and therefore that they are more likely to be dead. Because there’s a very high risk of death after being lost to a program. And we found that, yes, men were more likely to be lost to our system, but they were not more likely to be dead after being lost to follow-up. So that didn’t explain it. Maybe men are less likely to stick to their treatment? And we found that, in fact, there was absolutely no difference. No gender difference that we could find,” she said.

Researchers looked at other factors, such as whether there was a difference in suppression of HIV while on treatment. No answer was found there either.

“What is it? What could it be? Why? And I actually suddenly thought, well, why else do people die? Why do people die who don’t have HIV? And it was one of those I suppose eureka moments, where you suddenly realize you’ve been thinking inside a little box all this time. And you’ve been looking for all of the reasons within the antiretroviral program. But actually, possibly, the reasons lay outside it,” she said.

What she found was a much broader mystery with some stark facts.

“It’s not just in Africa and not just in South Africa. That in fact worldwide, men have twice the risk of death compared with women. And yet for some reason [it] does not seem to draw the kind of attention I think it deserves,” she said.

Cornell described it as a crisis. She said researchers cannot assume the mortality differences are merely the result of a failure of medical services or that men are to blame because of their behavior. She says when it comes to men gender differences are often ignored.

“I think that we have failed men,” she said, “I think that we haven’t found ways of offering men services which they think are important. Of offering them in a way which is accessible to them – male-friendly services – at times where they can make it. We really haven’t even looked at what are the obstacles. Why are men not coming in earlier?”

Cornell, a PhD candidate at the University of Cape Town’s School of Public Health, said she doubts it’s because men are just trying to tough it out. Cornell added that men are victims of gender inequality when it comes to health care and health status. She says it’s time to find how that can be changed.