Mortality rates are age adjusted to account for higher mortality in older populations and geographic variations in the ages of county populations.

“Researchers have long argued that where we live can help predict how we die. But how much our location affects our health is harder to say, because death certificates, the primary source for mortality data, are not always complete. They frequently contain what public health experts call ‘garbage codes’: vague or generic causes of death that are listed when the specific cause is unknown. Garbage codes make it difficult to track the toll of a disease over time or to look for geographical patterns in how people die. The data shown in the map above represents one research group’s effort to fill in these gaps.

Continue reading this article at FiveThirtyEight.com.