Figure 1.

Directed acyclic graph of the primary research question: “Is area deprivation index (ADI) associated with a diagnosis of chronic hepatitis C (HCV) for a federally qualified health center (FQHC) serving New Castle County, Delaware, USA?” The shaded box indicates that we may be inadvertently conditioning the relationship between ADI and HCV on the catchment of the FQHC, inducing selection bias. Demographic factors include age, race (white, non-white), and Hispanic ethnicity. Accessibility factors include insurance (non-private, private), number of previous visits in past 2 years, and access to public transportation (density of bus stops).