Lower socioeconomic status is associated with higher rates of death from coronary artery disease compared to higher socioeconomic status, and more than half of the disparities can be explained by four unhealthy behaviors. Dr. Yachen Zhu of the Alcohol Research Group, U.S., and Dr. Charlotte Probst of the Center for Addiction and Mental Health, Canada, report these findings in a new study published September 17 in the open-access journal PLOS Medicine.

Coronary artery disease, also known as coronary heart disease or ischemic heart disease, occurs when the arteries supplying the heart cannot deliver enough oxygen-rich blood due to plaque buildup, and is a major cause of death in the U.S. The condition poses a greater risk to people with lower socioeconomic status, but previous studies have reported conflicting results on whether certain unhealthy behaviours, like smoking, are primarily responsible for the observed disparities in deaths from the disease.

In the new study, researchers used data from 524,035 people aged 25 years and older whose mortality statuses were recorded in the National Death Index and who answered the National Health Interview Survey on demographics and health behaviours.

The team used education as the primary indicator for socioeconomic status and investigated four behavioural risk factors: smoking, alcohol use, physical inactivity and BMI. The four factors together explained 74% of the differences in mortality risk from coronary artery disease in men belonging to different socioeconomic levels and 61% in women.

The researchers conclude that their results highlight the need for effective public health policies and interventions that address each of these behaviours—both separately and together—because unhealthy behaviours often cluster among individuals from low socioeconomic backgrounds. They urge public health campaigns to raise awareness about heart health with messaging and outreach efforts customized for male and female audiences.

The authors add, "These efforts are crucial to reducing the socioeconomic disparities in deaths from coronary artery disease in the U.S."