Wide existing disparities in all-cause mortality between rural and urban U.S. regions are likely related to differences in socioeconomic status and access to health care (1). Cardiometabolic disease is the leading cause of preventable death in the United States (2), but since 2010, declines in heart disease mortality rates have slowed and stroke and diabetes mortality rates plateaued (3). Patterns of cardiometabolic death rates may differ in rural and urban regions and contribute to the well-described rural-urban mortality gap. To inform strategies for improving cardiometabolic health in all regions, we evaluated U.S. trends in cardiometabolic mortality by rural-urban status.
Using death certificates from the Centers for Disease Control and Prevention’s Wide-Ranging Online Data for Epidemiologic Research from 1999 to 2017, age-adjusted mortality rates (AAMRs) per 100,000 population from heart disease (HD) (International Classification of Diseases-10th Revision [ICD-10] codes I00 to I09, I11, I13, and I20 to I51) and cerebrovascular disease (CBD) (ICD-10: I60 to I69) as underlying cause were calculated using the 2000 U.S. standard population (2). The AAMR for diabetes mellitus (DM) (ICD-10: E10 to E14) was calculated using the multiple cause of death files for any mention of DM, which allowed us to more broadly quantify the burden of DM-related mortality. AAMRs were calculated by rurality (rural: micropolitan, noncore regions; urban: large central metropolitan, large fringe metropolitan, medium metropolitan, and small metropolitan regions) (4) across all and within each census regions (Northeast, Midwest, South, and West) as well as in race-sex groups (black and white, women and men). AAMR ratios quantified the number of rural deaths for every 1 urban death per 100,000 population. Linear regression was used to evaluate AAMR ratio trends between 1999 and 2017 SPSS version 21 (IBM, Armonk, New York). This study was exempt from institutional review board review.
Between 1999 and 2017, total HD-, CBD-, and DM-related deaths accounted for 2,405,818, 548,544, and 915,557 rural deaths, respectively; and 9,816,822, 2,178,079, and 3,551,458 urban deaths, respectively. There were 1.06 rural HD deaths for each urban HD death per 100,000 population in 1999, which increased to 1.21 in 2017 (p < 0.01). From 1999 to 2017, CBD rural-urban AAMR ratio was stable (1.13 to 1.09; p = 0.27); DM rural-urban AAMR ratio increased (1.09 to 1.30; p < 0.01). Rural-urban ratios differed across census regions by 2017 with the highest rural-urban AAMR ratios in the South for HD, CBD, and DM (1.32, 1.12, and 1.40, respectively). Rural-urban AAMR ratios were similarly low in the Northeast (1.08), Midwest (1.08), and West (1.09) for HD, and lowest in the West for CBD (0.96) and DM (1.01).
Race-sex trends in AAMR are shown in Figure 1. Rural black men had the highest HD and CBD AAMR. Rural-urban HD AAMR ratios significantly increased over time for all race-sex groups, but did not change for CBD mortality for any race-sex group. From 1999 to 2017, DM-related AAMR increased from 82 to 86 per 100,000 in rural regions, but declined from 75 to 66 per 100,000 in urban regions. Rural-urban DM AAMR ratio increased from 1999 to 2017 in black men (0.91 to 1.19; p < 0.01), white men (1.07 to 1.27; p < 0.01), black women (1.11 to 1.39; p < 0.01), and white women (1.16 to 1.37; p < 0.01).
FIGURE 1. Cardiometabolic Mortality in the United States, 1999 to 2017.
Age-adjusted mortality rates for (A) heart disease and (B) cerebrovascular disease are shown by race, sex, and rurality.
Disparities in cardiometabolic mortality between rural and urban Americans worsened between 1999 and 2017 within all race-sex groups for HD and DM. The widest rural-urban differences were attributable to divergent DM-related AAMR trends in rural and urban regions. Southern regions had the widest rural-urban disparities in cardiometabolic deaths. Cause-specific AAMR was higher in men versus women, especially rural black men. The higher rate of cardiometabolic mortality in rural Americans is undoubtedly multifactorial, and may in part reflect growing disparities in key risk factors and impediments to health care access in rural areas (1,5). Although these data limit evaluation of other race/ethnic groups and may be subject to misclassification, the comprehensive assessment of U.S. mortality burden reveals that rural-urban disparities in cardiometabolic mortality are persistent, are widening, and compound pervasive racial disparities. Focusing on cardiometabolic disease prevention and management by strengthening local systems of care or leveraging telemedicine may reduce disproportionately elevated mortality in rural regions. Complementary interventions at the individual, community, and national levels are needed to reduce the unacceptably high burden of cardiometabolic disease.
Acknowledgments
Research reported in this publication was supported, in part, by the National Institutes of Health’s National Center for Advancing Translational Sciences, grant number KL2TR001424 (to Dr. Khan) and National Heart, Lung, and Blood Institute grant number F32HL149187 (to Dr. Shah). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Research reported in this publication was also supported, in part, by the American Heart Association (#19TPA34890060 to Dr. Khan). The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Footnotes
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC author instructions page.
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