Examining Rural-Urban Disparities In Cardiovascular Death from 1999-2017

May 12, 2020
Patrick Campbell

A new research letter has found declines in rural areas have not been as pronounced as declines in metropolitan areas.

A new research letter is diving further into the disparities in cardiovascular mortality seen in rural and urban settings within the US from 1999-2017.

While the US has seen improvements in the rate of cardiovascular disease as a whole, the new letter outlines stark differences in age-adjusted mortality rates (AAMRs) across multiple subgroups based on a rural-urban area designation.

Using data from the US Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research (CDC WONDER) database, a team of investigators from multiple institutions analyzed trends in cardiovascular disease AAMRs—adjusting for age, sex, race, and ethnicity.

Age groups were defined as less than 25 years, 25-64 years, and 65 or older. Investigators used National Center for Health Statistics urban-rural classification criteria to define rural and urban areas—rural areas were defined as counties with a population less than 50,000.

Of note, investigators performed analyses assessing trends from 1999-2011 and from 2011-2017 based on a previous report suggesting reductions in cardiovascular disease mortality began to plateau after 2011.

Between 1999-2017, investigators identified a total of 16,111,775 deaths attributed to cardiovascular disease. Of these deaths, 80.3% occurred in counties classified as metropolitan according to the National Center for Health Statistics urban-rural classification criteria. Results of the analysis revealed a 37.46% decline in cardiovascular AAMR between 1999 and 2017 with rates of 350.8 and 219.4, respectively.

The absolute difference in AAMRs between large metropolitan areas in 1999 was 24 (95% CI, 22.1-25.9) deaths per 100,000 population and this gap widened to 42.8 (95% CI, 41.5-44.2) deaths per 100,000 population in 2017. Investigators pointed out the analysis indicated rural areas had consistently higher AAMRs than non-rural areas across all subgroups.

The analysis examining rates between 1999-2011 suggested an annual percent change (APC) of -4.1% (95% CI, -4.3% to -3.9%) in large metropolitan areas, -3.7% (95% CI, -3.9% to -3.5%) in medium and small metropolitan areas, and -3.2% (95% CI, -3.4% to -3.1%) in rural areas. From 2011-2017 decline in APC rates were -0.7% (95% CI, -1.0% to -0.4%) in large metropolitan areas, -0.5% (95% CI, -0.7% to -0.2%) in medium and small metropolitan areas, and -0.3% (95% CI, -0.5% to -0.2%) in rural areas.

Investigators also highlighted apparent increases in AAMRs among individual 25-64 years of age living in medium and small metropolitan areas, as well as those in rural areas, from 2011-2017.

Investigators noted multiple limitations within their study. Specific limitations included possible errors in documentation of race, ethnicity, and cause of death on death certificates. Investigators also noted the need for further research into the gap in AAMRs between rural and urban areas.

Check out a video from a 2019 visit with letter author Deepak Bhatt, MD, executive director of Interventional Cardiovascular Programs at Brigham and Women's Hospital and professor of medicine at Harvard Medical School, as he discusses progress made in the fight against cardiovascular disease.

This research letter, titled “Rural-Urban Differences in Cardiovascular Mortality in the US, 1999-2017,” was published in JAMA.