Drop in Cardiovascular-Related Deaths Possibly Linked to Economic Improvement

An investigation of economic data from 3123 US counties, from 2007 to 2016, indicates that the cardiovascular (CV) mortality drop the authors saw among middle-aged US adults may be a result of improved economic conditions. JAMA published the results of the retrospective analysis online today.

The implications for heart health, as well as detrimental effects resulting from a health care–associated disparity gap, prompted the authors’ analysis of any correlations seen between the baseline period of 2007 to 2011 and the follow-up period of 2012 to 2016. They used these 7 markers as indicators of economic prosperity:

1. Housing occupancy rate
2. County median household income:state median household income ratio
3. Percentage of 25- to 64-year-olds working
4. Percentage of adults with a high school diploma
5. Population with income above the poverty threshold
6. Percentage change in business during each time period
7. Percentage change in jobs during each time period

“After a decline in cardiovascular mortality for nonelderly US adults, recent stagnation has occurred alongside rising income inequality,” the authors stated. “Whether this is associated with underlying economic trends is unclear.”

With their primary outcome of annual percentage change (APC) for county-level, aggregated, age-adjusted CV mortality rate per 40- to 64-year-old (classified as middle-age) 100,000 individuals, National Center for Health Statistics provided the data on mortality, and the Distressed Communities Index, the economic data.

For the study years and the total population (N = 102,660,852 residents in the 7 counties; 51% women), the overall CV mortality rate was 0.95%, or 979,228. The greatest mortality decreases were seen in the intermediate and highest economic tertiles for change in economic prosperity:

• Intermediate tertile: mean (SD) of 104.7 (38.8) to 101.9 (41.5) deaths, a 2.7% overall improvement and APC change of –0.4% (95% CI, –0.8% to –0.1%)
• Highest tertile: 100.0 (37.9) to 95.1 (39.1) deaths, a 4.9% overall improvement and APC change of –0.5% (95% CI, –0.9% to –0.1%)

Similar notable changes were not seen in the lowest-economic-tertile counties, however. There, mean CV-related deaths actually rose from 114.1 (47.9) to 116.1 (52.7). This means there was a 1.8% uptick in CV deaths in these counties, for an APC of 0.2% (95% CI, –0.3% to 0.7%). Decreases were also seen in housing occupancy, income ratio, employed adults, and those with income above the poverty threshold.

Previous research shows that having just 1 social determinant of health can significantly increase the risk of mortality, particularly that related to heart failure.

Factors that may have contributed to the results seen in the lowest-tertile counties are that they had the following:

• Lowest median (interquartile range [IQR]) population: 7078 (3172-16,684)
• Highest percentage of rural residents: 25.9% (IQR, 10.9%-53.3%)
• Highest percentage of residents with diabetes: 9.1% (IQR, 8.0%-10.4%)
• Highest percentage of residents considered obese: 29.3% (IQR, 26.9%-32.4%)
• Lowest median total primary care physicians per 100,000 residents: 68.5 (IQR, 47.2-88.7)
• Lowest percentage of insured county residents: 85.8% (IQR, 81.3%-89.9%)

Overall, the mean rank for change in economic prosperity was 49.9 (13.9) (range, 5.4-91.9) for all counties analyzed, and diabetes and obesity increased in prevalence for all 3 groups of counties.

Following adjustment for baseline prosperity, demographics, and health care–related variables, the authors found a positive correlation between every 10-point increase in economic prosperity from baseline to follow-up and CV mortality, for an overall yearly 0.4% (95% CI, 0.2%-0.6%) mortality decrease.

“Counties with a higher mean rank had a greater increase, or lower decrease, in economic prosperity relative to counties with a lower mean rank,” the authors noted.

“There may be multiple mechanisms by which economic factors influence health,” they continued. “Job insecurity and income volatility may be associated with cardiovascular events. Worsening economic prosperity may lessen social cohesion and increase income inequality, contributing to a community’s health.”

Another possible reason, they noted, is the exodus of healthy people from areas in economic decline, which means a possible higher mortality rate for those who stay.

The relationship between economic trends and CV mortality should continue to be studies, the authors noted, in order to satisfactorily address the health care–associated outcome disparities brought on by income equality in the United States.

Reference

Khatana SMA, Venkataramani AS, Natham AS, et al. Association between count-level change in economic prosperity and change in cardiovascular mortality among middle-aged US adults. JAMA. Published online February 2, 2021. doi:10.1001/jama.2020.26141