If you haven't heard the phrase "treatment cascade" yet, you will. The creation of this concept is likely to shake out as one of the transformative moments in our understanding of the HIV epidemic in the U.S. It also provides a really cool reminder of how powerful it can be to portray data visually. So, whether you're familiar with the treatment cascade or not, it's worth spending a moment to go back over it.
The HIV treatment cascade "describes the journey that HIV-positive persons take as they navigate the health care system," as Kevin Fenton, M.D., Ph.D., then-director of the CDC's National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, eloquently put it. Originally published in a journal in March 2011, the cascade has been through various visual incarnations. Here's the original:
Here it is in a more simplified bar graph, lifted from a U.S. Centers for Disease Control and Prevention (CDC) fact sheet (read the fact sheet for more detailed breakdowns of the cascade by gender, age, race and risk group):
Bar graphs not doing it for you? How about a snazzy pyramidal version, for those of us who like to pretend we're upside-down in ancient Egypt?
Regardless of how it's portrayed, the great value of the cascade is that it displays exactly where the largest gaps are within the U.S. when it comes to getting diagnosed with HIV, getting into care and getting on successful treatment.
Before the cascade came along, the information we had on these gaps was much more sporadic -- and, maybe as important, was not portrayed in nearly as compelling or eye-grabbing a manner. We are creatures ruled by our senses, and we tend to understand difficult information better when it's presented in a format we can easily digest.
These data have spurred a huge amount of discussion and debate over the best ways to fill these gaps, and the factors that lead to them being so wide (particularly for some groups of people as compared to others, such as African Americans or people with low incomes).
Throughout this year, we'll be taking a closer look at various aspects of the treatment cascade. In the process, we hope to help shine a light on some of the reasons why so many people seem to get lost along the way to an undetectable viral load, as well as some of the ideas that our community's brightest minds have come up with for how to turn the cascade into a plateau -- with every person living with HIV in the U.S. on top of their diagnosis and treatment, rather than falling off one of the edges and being lost to the care they need.
To close, here's another visual representation of the treatment cascade -- a video from AIDS.gov.
Myles Helfand is the editorial director of TheBody.com and TheBodyPRO.com.