Visualizing Two Spatial Variables at Once

Context

PrEPárate was a social marketing campaign promoting pre-exposure prophylaxis (PrEP) treatments to prevent HIV infections among the Latine communities in the Chicagoland area. The campaign was released online— through a website and social media accounts of partner community organizations besides our own—, a hotline, and ads vehiculated on bus and train routes of the Southwest areas of Chicago, where most of the Latine community is located.

Problem

We needed to know our priority areas in the city of Chicago for the social marketing campaign, so we could vehiculate the right ads. Two variables were the most important: neighborhoods with the highest HIV incidence rates, and neighborhoods with the highest proportion of Latine population.

Unfortunately, it can be challenging to represent two variables simultaneously in a map.

Solution

I represented different HIV incidence rates by community area with a color scheme (a method also known as a choropleth map).

The South Side shows the highest concentration of new HIV diagnoses, while the Far North and Southwest Sides report minimal to no new cases, revealing stark geographic health disparities across the city.

Then, I filtered the Chicago community areas with 30% or more of Latine population.

Examining HIV incidence specifically within Chicago's Latino-majority neighborhoods reveals significant variation within this population. The highest rates occur in central communities, while outer neighborhoods show lower incidence, highlighting the need for neighborhood-specific prevention strategies rather than one-size-fits-all approaches to Latino health.

Results

We successfully vehiculated the campaign with the collaboration of our community partners and the Chicago Transit Authority. In the campaign, we focused on Southwest neighborhoods of Chicago, which were previously identified in my maps.