Lower Densities of Gastroenterologists, General Surgeons, and Radiation Oncologists in Rural vs Urban U.S. Counties
Geographic proximity to services has been identified as a potential barrier to cancer screening, and there is evidence of disparity in colorectal cancer outcomes between urban and rural U.S. residents. In a study reported in JAMA Surgery, Aboagye et al identified a significantly greater density of gastroenterologists, general surgeons, and radiation oncologists per 100,000 population in urban vs rural U.S. counties, a finding that may in part explain disparity in colorectal cancer outcomes.
Study Details
The retrospective population-based study involved data from the 2009 Area Resource File for the entire U.S. population within U.S. counties. Counties were categorized as rural (n = 1,807) or urban (n = 1,413), and the proportions of gastroenterologists, general surgeons, and radiation oncologists per 100,000 people in each county were estimated. Multivariate linear regression analysis adjusted for county-level socioeconomic variables, including percentages of females, blacks, population aged < 65 years without insurance, and persons with a high school diploma and median household income.
Greater Densities in Urban Counties
On unadjusted analysis, mean densities of physicians per 100,000 urban vs rural county population were 2.55 vs 0.39 for gastroenterologists (P < .001), 8.48 vs 4.82 for general surgeons (P < .001), and 1.01 vs 0.13 for radiation oncologists (P < .001). Multivariate analysis also showed significantly greater densities of physicians in urban counties, with absolute differences per 100,000 population of 1.63 (95% confidence interval [CI] = 1.40–1.85, P < .001) for gastroenterologists, 2.01 (95% CI = 1.28–2.73, P < .001) for general surgeons, and 0.68 (95% CI = 0.59–0.77, P < .001) for radiation oncologists.
A unit increase in the densities of gastroenterologists, general surgeons, and radiation oncologists in a county was associated with a percentage increase in the proportion of residents with a high school diploma (P < .001) and females (P < .001). There was no significant association between median household income and densities of general surgeons (P = .98) or radiation oncologists (P = .41); the density of gastroenterologists per 100,000 population in counties with median household income in the upper tertile (> $42,923) was greater than that for the lowest tertile (< $36,026; absolute increase = 0.34, P = .04), with no difference in density for the middle vs lowest tertile (P = .73). Increased percentage of people younger than 65 years without health insurance was associated with a decrease in the densities of gastroenterologists (−0.02, P = .006) and general surgeons (−0.15, P < .001), but not radiation oncologists (−0.01, P = .08).
The investigators concluded, “A rural-urban disparity exists in the density of gastroenterologists, general surgeons, and radiation oncologists who traditionally provide colorectal cancer screening services and treatment. This might affect access to these services and may negatively influence outcomes for colorectal cancer in rural areas.”
Awori J. Hayanga, MD, MPH, of the University of Pittsburgh Medical Center Presbyterian, is the corresponding author for the JAMA Surgery article.
The authors reported no conflicts of interest.
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