Figure 2.

Variations of the state-level utilization density of LDCT imaging and SDMC in quartiles, with an overlay of individual provider locations. Utilization density was defined as utilizations per 1,000 Medicare fee-for-service beneficiaries. States were grouped into three clusters, shown as three different colors (black, red, and green) for the state boundaries; those with blue color boundaries were states with no data. Clusters were generated based on three utilization variables (numbers of utilizations, Medicare fee-for-service beneficiaries, and unique providers) and four state-level factors (lung cancer mortality rate, prevalence of current smokers aged ≥ 65 years and former smokers, and median household income). See Figure 1 legend for expansion of abbreviations.