Differences in heart attack mortality have little to do with SES; traditional risk factors more influential

A new study from the Institute for Clinical Evaluative Sciences (ICES) shows that differences in heart attack mortality have little to do with socioeconomic status (SES), and that age and pre-existing cardiovascular risk factors are much more influential.

“Previous research has speculated that more affluent individuals have lower mortality rates after a heart attack because they have better access to specialty care and less psychosocial stressors than less affluent patients,” said study lead author and ICES scientist Dr. David Alter.

“However, our study has found that these factors actually have very little to do with patient outcomes following a heart attack.”

To conduct the study, investigators surveyed 3,407 patients hospitalized for a heart attack in 53 large-volume Ontario hospitals between December 1999 and February 2003 about their level of income, education, pre-hospitalization cardiac risks, and other illnesses. They linked this to 12 years’ worth of previous hospitalization data to examine the relationship among SES, health factors, and two-year mortality rates.

The results showed that differences in heart attack mortality rates between the high-income and low-income groups two years following their heart attack were reduced by 40% after age was taken into account, and an additional 26% after pre-existing cardiovascular risk factors were accounted for.

“Compared with more affluent persons, individuals in lower socioeconomic groups tend to lead less healthy lifestyles, frequently have more cardiovascular risk factors, and are more likely to sustain adverse cardiovascular events over time,” said Dr. Alter.

“Therefore, traditional risk factors may be the driving mechanisms behind disparities between income and mortality rates after a heart attack, and we can most successfully reduce the burden of heart disease by addressing known vascular risk factors, particularly among those who are socially disadvantaged.”

The study, “Socioeconomic status and mortality after acute myocardial infarction”, is in the January 17, 2006 issue of the Annals of Internal Medicine.

Author affiliations: ICES (Drs. Alter, Austin, Williams, Tu, and Naylor, and Ms. Chong and Ms. Iron); Division of Cardiology, Schulich Heart Centre, (Drs. Alter and Morgan), and Department of Medicine (Drs. Alter, Morgan and Tu) Sunnybrook and Women’s College Health Sciences Centre; Department of Psychology (Dr. Irvine), and the President’s Office (Dr. Naylor) University of Toronto; Institute for Work and Health (Dr. Mustard).

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.

FOR FURTHER INFORMATION, PLEASE CONTACT:

• Julie Dowdie
• Media Relations Officer, ICES
• (416) 480-4780 or cell (416) 432-8143