Dr Mary Cushman: Disparities in Pulmonary Embolism Exist; We Need to Ask Why

Mary Cushman, MD, professor of medicine at the University of Vermont, director of the thrombosis and hemostasis program at the University of Vermont Medical Center, expands on the findings of a study on social determinants of health and disparities in hospitalization, treatment, and mortality in patients with pulmonary embolism (PE).

These findings were presented at the 64th American Society of Hematology (ASH) Meeting & Exposition, which was held December 10-13, 2022, in New Orleans, Louisiana.

The American Journal of Managed Care^® (AJMC^®): What were some of the main findings of your study on social determinants of health and pulmonary embolism (PE) treatment and mortality?

Cushman: We studied data from the Nationwide Inpatient Sample, which is a random sample of 20% of all hospitalizations in the United States, between 2016 and 2018. We ascertained all pulmonary embolism hospitalizations, whether a person was admitted for pulmonary embolism or PE, or had PE during the hospitalization, and analyzed the patterns of care and the outcomes of people based on social determinants of health, specifically race and ethnicity, insurance type, and income level. We found that there were differences in the presentation of PE, the treatments that were administered, and the fatality rates.

For example, amongst all people admitted for PE, those admitted with what we call high risk PE or PE that's more serious, were more likely to be Black individuals and Asian Pacific Islanders, relative to White people, with no differences between other racial groups and White people. We also showed that the actual overall hospitalization rate differed dramatically by racial group. The rate per 10,000 of the [overall] population for admission for PE was about 15. Amongst Black people, it was 20 per 10,000. Amongst Asian and Pacific Islander people, it was 3 per 10,000. White people had a rate of 13 per 10,000.

We found that about 5.5% of all patients received what we call advanced therapies or more aggressive therapies for their PE, and amongst those with high risk PE, that percentage was 19%. And there were differences by social determinants in the administration of these advanced therapies. Black people and Asian Pacific Islanders were less likely to receive advanced therapies, and people who had their primary health insurance as Medicare or Medicaid were also less likely to receive these more aggressive treatments compared to people with private insurance. We didn't see any difference by income in the use of those treatments.

For in-hospital mortality amongst all patients, Asian, Hispanic, and people of other racial groups had a greater in-hospital mortality. But if you look just at the people with the most serious PE, which we call high-risk, PE, the mortality rates in all the non-White groups were greater than [those in] White people. They ranged between 10% and 50% greater in terms of the mortality in those groups. That's really important because the mortality rate in that group with high-risk PE was actually 50%, so 1 in 2 people with that type of PE actually died in their hospitalization.

Now, all of these figures I'm giving you are adjusted for all other factors that we thought might be confounders or might be alternative explanations for these findings. In sum, non-White people were more likely to experience high-risk PE, the advanced therapies were less often used in Black people and Asian and Pacific Islanders, and Black, Asian, and Hispanic people were more likely to present with high-risk PE and die in the hospital than White people.

AJMC^®: Did your study indicate anything about the relationship between social determinants with treatment and course of PE based on race?

Cushman: We know, historically and persisting for a long time, that Black people have twice the death rates from pulmonary embolism compared to other groups in our country, with other groups all kind of similar to each other. We also know that Black people have a greater incidence of pulmonary embolism. Our findings extend that by showing that they're less likely to receive more aggressive treatments for their PE, and they're more likely to die in hospital once they have PE. So the question is, why is this?

Our findings were independent of the other social determinants that we had data for, like neighborhood income level, insurance status, what type of hospital they were at—whether it was a rural or urban hospital, or larger or smaller hospital, or a teaching hospital or not. But we didn't have a lot of granular data to help further explain it. For example, we don't know the education level of people. These are administrative data and that's not data that's recorded in hospital records, so we didn't know education level, for example, or quality of education. There's so many more questions that need to be addressed to understand these patterns that we're seeing. All we're seeing are patterns. We can't say why they're there. We can say, yes, they seem to be independent of these other factors that we adjusted for our analysis, but that's not a perfect way to try to address those other factors as causes.

Obviously, it's not the color of a person's skin or anything about their ancestry that is causing these disparities. My hypothesis is that structural racism is at the root of these differences that we're seeing. And structural racism is imposed by historical policies of the past that segregated people, for example, which led Black people to have lesser quality education and to live in places where they didn't have advantages compared to other groups, and leads to interpersonal racism today.

So, those things really need to be addressed and studied to see if they explain any of these differences. For example, if a Black person might be less well-educated or less in touch with resources, they might not know when they're having symptoms that are serious. If they're having shortness of breath or chest pain, symptoms of PE, they may not know to go get checked. They may not trust the system; there's a lot of reasons why they wouldn't trust the system. So, if they don't trust the system, they may not go to care as quickly as someone who trusts the system. And, of course, people working in health care have unconscious biases that creep into how they view the world and how they care for patients.

If we as health care providers aren't acknowledging that and watching for it to make sure our treatments are being given equitably, then that's on us. We need to address all of these questions and try to figure out what it is that's causing these these differences that we're seeing.