For public health workers, it’s no surprise that social, economic and political conditions shape the distribution and burden of disease. They’ve always known that it takes much more than medicine to keep people healthy. Still, when public health scientist Kristina Talbert-Slagle decided to study the impact of social and public health spending on HIV/AIDS, she wasn’t sure what she’d uncover.

“We thought that maybe there would be a connection, but we didn’t really know what to expect,” said Talbert-Slagle, a senior scientific officer at the Yale Global Health Leadership Institute and a lecturer in the Yale School of Public Health. “So I was a bit surprised to see a connection to all three outcomes we studied: HIV cases, AIDS cases and AIDS deaths.”

In a first-of-its-kind study, Talbert-Slagle and her research colleagues examined the association between state-level spending on social services and public health and HIV/AIDS cases and deaths across the country. The retrospective study, which was recently published in the journal AIDS, is based on 2000-2009 data from a variety of sources, including the U.S. Census, Centers for Medicare & Medicaid Services, the Centers for Disease Control and Prevention, and state public health departments. They found that higher state spending on social services and public health was indeed associated with reduced HIV/AIDS case rates and AIDS deaths one year later.

In particular, they found that higher spending on education per person living in poverty was “significantly associated” with lower HIV and AIDS case rates as well as fewer AIDS deaths per 100,000 people. The found that greater spending on income support was “marginally associated” with declines in HIV case rates. Also, more spending on public health per person living in poverty was significantly associated with declines in AIDS cases and AIDS deaths and marginally associated with reductions in HIV cases. Talbert-Slagle and study co-authors Maureen Canavan, Erika Rogan, Leslie Curry and Elizabeth Bradley write:

This effect was observed not only for social service and public health spending from the previous year, but also when we incorporated spending from 5 years earlier and persisted even after adjusting for health care spending and socioeconomic factors that vary across the states. To our knowledge, this is the first study that explicitly establishes a significant association between key state-level social services investments and clinical health outcomes for people at risk of HIV infection or for those living with HIV/AIDS. This work highlights a potentially critical element, often missing from health policy discussions, in improving outcomes for this important population.

Talbert-Slagle told me she wants to be very clear about her findings: The study didn’t uncover a cause-and-effect link between state spending levels and HIV/AIDS outcomes — instead, it reveals an association. However, the study does add itself to a growing body of literature on the impact between social services and public health spending and disease outcomes, underscoring the notion that effectively managing and preventing disease goes far beyond the walls of a doctor’s office. (For example, this 2011 study from Health Affairs found that for each 10 percent increase in local public health spending, mortality rates from preventable causes of death fell by up to 6.9 percent.) Recognizing that caring for people living with HIV/AIDS comes with a mix of medical and public health difficulties, the study noted that “social factors such as housing, food insecurity and transportation may affect a patient’s likelihood of receiving care or adhering to an antiretroviral medication regimen.”

So, what do these findings mean in the wider context of the HIV epidemic? First, consider these statistics. According to the latest federal data, there are more than 1.2 million people living with HIV in the U.S., and about 14 percent are unaware of their HIV status. Every year in the U.S., about 50,000 new HIV infections occur, and that number has remained stable for about a decade. In addition, among people living with HIV, only about a quarter have their viral loads under control, which affects the person’s health, quality of life and the risk of transmission.

The bottom line is that despite the progress made so far in battling HIV/AIDS and caring for those affected, we still have a long way to go in both the prevention and treatment realms. And so a study such as the one Talbert-Slagle and her colleagues conducted reminds us that diseases such as HIV/AIDS are social challenges as well as medical ones.

“We can’t deny the importance of medical care and treatment in the sphere of HIV/AIDS,” she told me. “But the key message for policymakers is that when we think about health care spending, let’s not separate it from spending on social services. …Wouldn’t we be better off investing in social services to prevent a person from coming into a hospital with AIDS and opportunistic infections? Doesn’t it make sense to think early on about investing in all the services that a person needs to prevent that scenario? And not just for that person, but for all of us?”

To download a full copy of the new study, visit AIDS.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for nearly 15 years.