Income Volatility Linked with Two-fold Increased Risk for Cardiovascular Disease and Mortality

Income volatility during formative earning years was associated with a nearly two-fold risk of cardiovascular disease (CVD) and all-cause mortality, new study results suggest.

Researchers for the study, publishing in Circulation, sought to characterize associations between income volatility (between 1990 and 2005) with incident CVD and all-cause mortality in the subsequent decade.

“Income volatility is on the rise and presents a growing public health problem,” the researchers wrote in the study abstract. “Because in many epidemiological studies income is measured at a single point in time, the association of long-term income volatility with incident CVD and mortality has not been adequately explored.”

The analysis included 3,937 black and white participants in the Coronary Artery Risk Development in Young Adults (CARDIA) Study between 23 and 35 years of age. The study defined income volatility as the intraindividual standard deviation of the percent change in incomes across five assessments between 1990 and 2005. Income drop was defined as a decrease of 25% or more form the previous visit and less than the participant’s income. Mortality and CVD events were adjudicated using medical records and death certificates.

Links Between Cardiovascular Events and Income

The researchers reported 106 CVD events and 164 deaths between 2005 and 2015. Using Cox models adjusted for sociodemographic, behavioral and CVD risk factors, the results indicated that higher income volatility and more frequent income drops were independently associated with a greater risk for CVD (high vs. low volatility: HR=2.07; 95% CI, 1.10 to 3.90; ≥2 versus 0 income drops: HR=2.54; 95% CI, 1.24 to 5.19) and all-cause mortality (high vs. low volatility: HR=1.78; 95% CI, 1.03 to 3.09; ≥2 versus 0 income drops: HR=2.54; 95% CI, 1.07 to 3.44).

“The findings of this study reinforce the urgency and growing public health threat associated with income volatility in the United States,” the authors wrote in their conclusion. “Given the current economic environment of increasing income instability, understand how the income volatility is associated with health has become increasingly important.”

What Can Be Done

In an accompanying editorial, Erica Spatz, MD, and Jeph Herrin, PhD, of Yale University, highlighted the multifaceted nature of financial difficulties that affect both daily life and physical health.

“Elfassy et al’s study reminds us that income volatility is at least a double hit—affecting not only one’s pocket but also one’s health,” they wrote in the editorial.

They noted that changing times and updated community-based models may be able to help patients get where they need to go.

Financial losses incurred early in life, even if followed by financial recovery, can have long-term effects, [and] acting on this information to improve population health may be challenging,” they wrote. “However, with new models that hold communities and health systems accountable for the health, quality, and cost of their population, there is now a business case for communities and health systems to screen for financial toxicity, connect at-risk patients with needed financial and social support services, and increase surveillance for the physiological effects of income volatility and other financial hardships.”

Source: Circulation: Associations of Income Volatility With Incident Cardiovascular Disease and All-Cause Mortality in a US Cohort; Cardiovascular Outcomes in the Wake of Financial Uncertainty