Poverty Tied to Poor Stress Test Score

Feb. 14, 2006 -- New research links poverty to poorer performance on exercise stress tests for coronary artery disease.

The finding comes from a study of about 30,000 people in Ohio with known or suspected coronary artery disease. Participants took exercise stress tests on treadmills at The Cleveland Clinic.

Poor test performance was linked to poverty and to higher death rates during follow-up, which lasted for an average of 6.5 years.

The study appears in The Journal of the American Medical Association. The researchers included Mehdi Shishehbor, DO, MPH, of The Cleveland Clinic's cardiovascular medicine department.

Treadmill Test

Participants lived in seven Ohio counties. They had been referred to The Cleveland Clinic for an exercise stress test between 1990 and 2002.

The researchers estimated socioeconomic status based on the patients' home addresses and U.S. census data. They also noted the patients' medical insurance and employment status.

The exercise tests monitored participants' hearts during exercise and immediately afterwards.

Most patients took the exercise test to screen for coronary artery disease. Others already knew they had coronary artery disease and took the test as a follow-up.

Poverty's Pattern

Poverty was linked to poorer test performance, even after taking other factors into account, the study shows.

People with low socioeconomic status tended to perform worse on the treadmill tests. They were also more likely to be minorities and to have a higher BMI (body mass index), diabetes, high blood pressure, and a known history of heart disease.

Participants were followed for an average of 6.5 years. During that time, a total of 2,174 participants died of any cause. The poorest group had the highest death rate.

The researchers split participants into four brackets based on socioeconomic status. Deaths included 10% of patients in the lowest bracket, compared with 5% of those in the highest bracket.

The study doesn't prove that poverty was to blame for those deaths. However, the researchers note that if their findings are confirmed, more attention should be paid to closing health gaps between people living in poverty and the rest of society.