Examples of possible degrees of population-level HIV/socioeconomic associations.

<p>Cities were sorted by various 2000 population metrics (x-axes), and the HIV incidence averaged over quartiles, where Q1 represents the average HIV incidence for the 20 cities with the highest values for that census metric and Q4 the average HIV incidence in the 20 cities with the lowest values for that census metric. T-test comparison of the HIV values in first and fourth quarters illustrates that many metrics are associated with HIV incidence (A, B, E, F, I), while others weakly associate (D, G, H) and still others are not likely to be associated (C). Bars = SEM.