The County Health Rankings (CHR) measured four types of health factor: (1) health behaviors of residents; (2) access and quality of clinical care; (3) various socio-economic elements, such as household income and education attainment; and (4) overall quality of physical environment.
The Wall Street Journal columnist Melinda Beck broaches the research results:
On suburbia living: "In many measures, residents of suburban areas are the best off. They generally rate their own health the highest and have the fewest premature deaths than either their urban or rural counterparts. Suburbanites also have the fewest low-birth-weight babies, homicides and sexually transmitted diseases."
On city living: "[C]ity dwellers live with more air pollution and violent crime. They also have higher rates of sexually transmitted diseases and low-birth-weight babies and are more likely to drink excessively. But overall, urbanites tend to rate their own health more highly and are less likely to die prematurely than rural Americans."
On rural living: "Rural residents are now more likely than other Americans to be obese, sedentary and smoke cigarettes. They also face higher rates of related health problems including diabetes, stroke, heart attacks and high blood pressure. [...] About 25% of the U.S. population lives in rural areas, but they are served by only 10% of the country's physicians. They are also less likely to have private health insurance, prescription drug coverage or be covered by Medicaid."