Urban HIV incidence by exposure category from 1998–2002 as a function of socioeconomic and demographic metrics of 80 U.S. cities in 2000 (unless otherwise indicated).

HIV association factor is the ratio between HIV incidences for Q4 and Q1, or, for starred metrics (*), Q1:Q4* (for easier comparison where a smaller metric value theoretically predicts greater risk). For each population, HIV incidence was obtained by dividing the total number of HIV cases for that single exposure category by the total population. Boldfaced = p<0.05 for similarity between Q1 and Q4 (Student's T-test).