Who knew a $30,000-a-year tuition could buy you a few extra years of life?
A new, internationally conducted Medical Center study revealed that people with a college degree and a white collar job can expect to live longer after a heart attack.
"The less education you have, the more likely you are to die within a year [of a heart attack]," said Dr. Conor O'Shea, a Duke Clinical Research Institute cardiologist and lead author of the study.
The study analyzed socioeconomic data collected from an international trial that included over 15,000 patients from over a dozen countries.
O'Shea explained he used a traditional marker of wealth, the number of years of education, to represent socioeconomic status.
Information about actual household income is very difficult to collect due to privacy issues, and looking at zip codes is often an unreliable way of determining wealth.
O'Shea's team modified the raw data to adjust for relevant factors like age and also limited the study's international scope to only include countries where at least 500 patients were enrolled, thereby narrowing the field to 11,300 patients. Using this new data set, the researchers discovered that 19.8 percent of patients with less than eight years of education died within a year after the heart attack, compared with only a 3.5 percent death rate among patients with over 16 years of education.
Additionally, the death rate for patients who worked in management positions was 3.8 percent versus 5.1 percent amongst the laborers.
O'Shea did not attribute these findings to any specific factors but speculated that lower socioeconomic status may be associated with increased smoking, an inability to vary one's diet and lowered access to cardiac intervention and medication.
Factors like these play prominent roles in increasing the risk of dying within one year of a heart attack.
O'Shea's next project will focus on identifying the dynamics of these factors in educated and less-educated populations.
The study's raw data also initially indicated that patients who live alone are at a greater risk of dying after a heart attack, but the adjusted data was not conclusive because the majority of the patients who lived alone were also older.
"The data was driven by the older age of patients," said O'Shea.
"When the data was adjusted [for patients' age] it didn't show an increased risk of dying."
The international nature of the trial made the data analysis process a bit different than most Medical Center research projects.
In addition to translation and data collection challenges, cultural differences had the potential to seriously alter the study's results.
For example, when researchers attempted to ascertain how much alcohol the patients consumed on a daily basis, definition problems arose.
"A beer to an American is 12 ounces versus a liter to a German," said DCRI senior statistician Amanda Stebbins.
To compensate for such occurrences, Stebbins explained, international trials use steering committees that help modify the study's design to reflect the specifics of the countries involved.
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