Poorer patients in the U.S. may be less likely to get their blood pressure under control, even when they are participating in a clinical trial where medication and doctor’s visits are provided free of charge, a new study finds.
Compared to patients from the wealthiest counties, those from the poorest counties were half as likely to get their blood pressure under control during a six-year-clinical trial, researchers report in the Journal of the American Heart Association.
“We found that even if everyone is going to the doctor and getting their medications, there are still differences based on the socioeconomic context under which they live and obtain their care,” said the study’s lead author Dr. Andi Shahu, a resident physician at Johns Hopkins Hospital. “Our hypothesis moving forward is that maybe other social factors we are not measuring well could be at play here.”
“There are lots of reasons why these disparities may exist,” Shahu said. “For example, people who live in a lower socioeconomic county may feel less safe (possibly because of higher crime rates). They may not have access to healthy food. They may not be able to exercise or do other things to support their heart health in addition to taking medication.”
To take a closer look at the impact of socioeconomic status on blood pressure control, Spatz and his colleagues reanalyzed data from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). In that trial, hypertensive patients were randomly assigned to receive one of three blood pressure lowering drugs for six years to test whether any one was better than the others. The study used 140/90 mm Hg as the threshold for high blood pressure designation. The current American Heart Association guidelines lowered the cutoff to 130/80 mm Hg.
The researchers focused on 27,862 ALLHAT participants. Because ALLHAT didn’t collect information on each participant’s income, Shahu and his colleagues used the income level of the county where study participants went to get their care. That meant 2,169 patients fell into the lowest income bracket as compared to 10,458 receiving care in the highest income counties.
Participants in the lowest income group were more likely to be women, to be black, to be Hispanic, to have fewer years of education, to live in the South and to have fewer cardiovascular risk factors.
When the researchers compared the patients from the poorest counties to those from the wealthiest, they found, after accounting for cardiovascular risk factors, that patients were 52% less likely to reach the blood pressure goal of 140/90 mm Hg, were 25% more likely to die from any cause, were 26% more likely to be hospitalized or die from heart failure and 86% more likely to develop end-stage kidney disease.
They were also 30% less likely to be hospitalized for chest pain and 29% less likely to undergo cardiac revascularization, a procedure to open up blood vessels. Shahu suspects that last statistic, while sounding like an advantage, might simply be the result of patients not having access to the procedure. “Other studies have shown that people in lower socioeconomic communities, and minorities in particular, are less likely to receive these procedures because of lack of access to care,” Shahu said.
The new findings are “really upsetting,” said Dr. Suzanne Steinbaum, director of Women’s Cardiovascular Prevention, Health and Wellness at The Mount Sinai Hospital in New York City. “This is a six year trial where the patients had access to medication and doctors’ visits. All these bigger issues are taken care of, but we see that patients from lower socioeconomic counties have less of a chance of getting their blood pressure under control—and that’s when they were aiming for 140/90 mm Hg, and not the current 130/80 mm Hg.”
One big issue unaccounted for in the original study was whether patients were taking their blood pressure medications as prescribed, Steinbaum said. The new findings may be a sign that patients aren’t getting properly educated about the importance of their medications, she added.
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