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Americans living in rural areas had higher rates of preventable premature mortality from the five leading causes of death than those living in urban areas during the years 2010-2022, and the divide only appears to be growing, a CDC analysis showed.

During this period, the mortality gap between the most rural and most urban U.S. counties decreased for unintentional injury but increased for cancer, heart disease, chronic lower respiratory disease (CLRD), and stroke, according to researchers led by Macarena Garcia, DrPH, a senior health scientist at CDC's Office of Rural Health.

"When assessed by the six urban-rural county classifications, percentages of preventable premature deaths in the most rural counties (noncore) were consistently higher than in the most urban counties (large central metropolitan and fringe metropolitan) for the five leading causes of death during the study period," they wrote in .

The gap in all-cause mortality between rural and urban areas of the U.S. has continued to widen over the past few decades, the authors noted in their introduction.

"In 1999, the death rate in rural areas was 7% higher than in urban areas; by 2019, it was 20% higher," said Garcia and colleagues, noting that structural factors like lower socioeconomic status and limited access to healthcare providers have been shown to play a role. In addition, "because each of the five leading causes of death is age-related, these conditions are more prevalent in rural areas of the United States where residents typically are older than their urban counterparts."

Furthermore, "the risk for premature death is associated with modifiable factors that vary by disease," the investigators wrote. "Four of the five leading risk factors for premature death are more prevalent in rural areas of the United States: using tobacco, obesity, physical inactivity, and drinking alcohol or drinking in excess."

To look at the issue in detail, the researchers used mortality data for U.S. residents from the to calculate preventable premature deaths by urban-rural county classification from the five leading causes of death during 2010-2022. Deaths from COVID-19 were excluded to maintain consistency and facilitate the assessment of trends over time. Data for 2022 are provisional counts from January through June and were "annualized" to compare with previous years.

Age-specific mortality rates for each of the five leading causes of death were used to derive the number of preventable premature deaths, they explained. Age groupings varied by cause of death. For each age group and cause of death, the death rates of the three "benchmark states" with the lowest rates during 2008-2010 were averaged to produce "benchmark rates." These benchmarks were chosen to represent the lowest death rates achievable by states at the beginning of the study period. The percentage of preventable premature deaths was calculated by dividing the number of preventable premature deaths by the total observed number of premature deaths.

In deaths for which COVID was a contributing cause, the underlying cause of death was counted, rather than COVID, Garcia said in a press briefing. "In our methodology, we're only looking at the underlying cause of death ... because it's the simplest to use," she said. "So COVID was not an additional cause of death we looked at."

Overall, premature preventable death rates for Americans increased for unintentional injury -- such as poisoning, drug overdose, car crashes, drowning, and falls -- and stroke during the years studied, but dropped for cancer and CLRD and remained stable for heart disease, the researchers found.

The percentage of preventable premature deaths from cancer decreased from 2010 through June 2022, from 21% to 0.3%, the authors found. Although all county categories experienced decreases, the drops in urban counties were larger than those in rural counties. The percentage of premature deaths from cancer in rural areas in 2022, for example, was 18.1%, which was similar to the 17.9% in large urban counties in 2010.

However, Garcia cautioned during the press briefing, that drop to 0.3% for preventable cancer deaths was based on a benchmark from more than a decade ago. "That doesn't mean there are no more preventable early deaths for cancer," she said. "We need to update that benchmark, and we'll be able to see what that looks like today."

The percentage of preventable premature deaths from heart disease decreased from 2010 through 2019, from 33.5% to 28.8%, followed by a steep increase to 33.6% from 2020 through June 2022, the investigators said. Most states experienced an increase in preventable early deaths from heart disease and stroke (96% and 88% of states, respectively) from 2019 through June 2022.

The percentage of preventable premature deaths from CLRD decreased from 2010 through 2022, from 38.6% to 25.5%, the study found. "The percentage of preventable premature deaths varied widely when stratified by rural-urban county category, but all county categories except for noncore counties experienced decreases," the authors noted.

"Routine tracking of preventable premature deaths by urban-rural county classification might facilitate the identification of areas with high prevalence of preventable premature mortality," the investigators concluded. "Findings might help guide more focused interventions to reduce premature death from the five leading causes of death and reduce disparities by rural-urban residence and geographic region."

The authors listed several limitations to their study. These included the fact that applying benchmarks to all urban-rural county categories facilitates comparisons but might not represent the lowest death rates achievable by certain subgroups; that differences cannot be attributed solely to population size and geographic location because risk factors do not occur randomly in populations and are related to well-known social, demographic, environmental, economic, and geographic attributes of the neighborhoods in which persons live and work; and that estimates of probable premature deaths using historical benchmarks (e.g., 2008-2010) might not reflect improvements in mortality that could have occurred in a later year.

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