Around the World, Finances Impact Acute MI Outcomes in Older Adults

Even when they have government-run universal health insurance, older adults with low incomes consistently have worse outcomes than those with high incomes when they experience an acute MI, international data show. But in a surprise to researchers, individuals living in the US didn’t see the largest wealth-related gaps.

The analysis, published today in JAMA, sought to tease out effects of income across the world by looking at the experiences of six countries: the United States, Canada, England, the Netherlands, Taiwan, and Israel.

All have “highly developed healthcare systems and accessible administrative data but [also] have significant differences in financing, organization, and performance in international rankings,” Bruce E. Landon, MD, MBA (Harvard Medical School, Boston, MA), and colleagues write. “We hypothesized that despite each country offering universal insurance for older adults, there would be larger income-based disparities in treatment and outcomes in the US than in other countries, notwithstanding the fact that low-income older adults would do worse in all countries.”

This turned out not to be the case. Despite the “important and deeply held belief” that the largest disparity would be seen in the US—where Medicare insurance covers most older adults, but there’s much freedom for wealthier people to seek out higher-quality physicians and hospitals—all six nations showed income-related imbalances in care and outcomes for acute MI, the researchers report.

Less-aggressive management or unmeasured confounders could be driving the differences, they note. No matter the reason, “these findings of increased mortality of a similar magnitude for lower-income patients in all countries suggest that poverty and disadvantage are problems that afflict all countries irrespective of history, culture, healthcare system, and social safety net.”

Indeed, the findings were unexpected, Landon told TCTMD in an email. “The common story is that the US does worse. We don’t have a unified healthcare system [and] lack social supports and a strong safety net,” he said, adding that the findings across the diverse countries they studied were quite consistent. “Being poor seems to be bad even in these countries that are seen as more egalitarian.”

Being poor seems to be bad even in these countries that are seen as more egalitarian. Bruce E. Landon

Landon et al used population-representative administrative data to look at adults ages 66 and up who were hospitalized with acute MI across the six countries between 2013 and 2018.

They identified a total of 289,376 patients with STEMI and 843,046 with NSTEMI, dividing them into quintiles by income. In most regions, income was ascertained by postal code, though in the Netherlands the information was available at a household level.

Cardiac catheterization and PCI were more commonly performed in highest- versus lowest-income patients, with absolute differences ranging from approximately 1% to 6%. CABG surgery did not differ by income for STEMI patients but was more often used in the wealthiest versus poorest quintile for NSTEMI patients, with absolute differences ranging from approximately 1% to 2%. Hospital stays were shorter for wealthier patients, except in Israel and Taiwan.

Across the countries, apart from Taiwan, adjusted 30-day mortality rates were lower for patients with the highest income. The absolute difference between the wealthiest and poorest quintiles of those with STEMI, for example, ranged from 1.7% in England up to 2.9% in Canada, with the US falling in the middle at 1.8%. Readmission rates within 30 days were lower in the highest-income patients.

By 1 year after acute MI, the gaps in mortality had grown larger and again Taiwan stood out for its lack of difference. For STEMI patients, the largest disparity between the wealthiest and poorest quintiles—nearly 10%—was seen in Israel (16.2% vs 25.3%) and the smallest in England and the United States (17.7% vs 20.5% and 27.0% vs 29.8%, respectively).

“These results suggest that in contrast to findings from other studies, the US is not an outlier in terms of the care provided to and outcomes among patients with low versus high incomes for the population of older patients admitted with an acute MI,” the authors conclude.

Going into their study, the researchers had expected “places like the Netherlands and England (and maybe Canada), which have stronger social supports and a uniform healthcare system, would have performed better,” said Landon. “I think that our findings challenge long-held assumptions that other countries have figured this out.”

What’s clear, he continued, is that the problem of low-income patients having worse outcomes “is near universal and that countries need to intensify efforts to improve care for the most vulnerable.”

Acute MI, though, is just one condition; others deserve to be examined, Landon added. “At some point, we also will need interventions to improve care for these patients and we also need to better understand the contribution of within-hospital care differences versus poor people getting care from different hospitals.”