Where You Live Matters: The Impact of Place of Residence on Severe Sepsis Incidence and Mortality.

BACKGROUND: Medically underserved areas are composed of vulnerable populations with reduced access to ambulatory care services. Our goal was to determine the association between residence in a medically underserved area and severe sepsis incidence and mortality.

METHODS: Using administrative data, we identified adults admitted with severe sepsis to nonfederal hospitals in South Carolina. We determined whether each resident lived in a medically underserved area or nonmedically underserved area from US Census and Department of Health and Human Services data. Age-adjusted severe sepsis incidence and mortality rates were calculated and compared between both residential classifications. Multivariate logistic regression measured the association between residence in a medically underserved area and mortality while adjusting for confounders.

RESULTS: In 2010, 24,395 adults were admitted with severe sepsis and 1,446,987 (43%) adults lived in a medically underserved area. Residents of medically underserved areas were admitted more frequently with severe sepsis (8.6 vs 6.8 cases/1,000 people, P < .01) and were more likely to die (15.5 vs 11.9 deaths/10,000 people, P < .01), with increased odds of severe sepsis-related death (OR, 1.12) after adjustment for age, race, and severity of illness. ZIP code-based surrogates of socioeconomic status, including median income, proportion below poverty level, and educational attainment, however, had minimal association with sepsis mortality.

CONCLUSIONS: Residence in a medically underserved area is associated with higher incidence and mortality rates of severe sepsis and represents a novel method of access-to-care adjustment. Traditional access-to-care surrogates, however, are poorly associated with sepsis mortality.