Patients from communities blighted by poverty might receive slightly higher cumulative radiation doses from diagnostic imaging, but only because they're probably just sicker, according to a new study.
Previous studies looking at this issue have been mixed: a Canadian report from 2005 found that richer patients had greater access to all forms of radiological imaging. That makes sense, as richer people tend to have better access to health care in general. But a Taiwanese study from 2008 found that poorer patients got more CT scans, according to the new report.
This matters because CT scans account for about half of Americans' medical imaging dose, and medical imaging itself accounts for about half of Americans' total population exposure, so increased use of CT could put poorer folks at risk.
Although the health effects of low-dose medical radiation are
controversial in some quarters, in general doctors try to use the lowest amount possible.
But the current study, published in the January issue of the Journal of the American College of Radiology, found poverty, while taking a toll on health, did not up risks for imaging radiation exposure.
Poor neighborhoods
In the retrospective study, doctors examined the records of about 10,000 patients who had imaging done at outpatient clinics of Montefiore Medical Center in the Bronx, one of the poorest areas in the country. According to their study, eight out of 10 patients lived in a neighborhood where more than 10 percent of the population struggled below the poverty line, a common marker of a place's socioeconomic ranking. And nearly two-thirds lived in areas with more than 20 percent poverty.
Around half the population in the study were Hispanic, about one-third black, 10 percent white and 2 percent Asian, according to the researchers who wrote the report, Dr. Daniel Strauchler, Katherine Freeman and Dr. Todd S. Miller. The patients were all between the ages of 21 and 40, as radiation risks drop after that age, the researcher said.
Health toll
As expected, men and women on public health insurance, living in poverty-stricken neighborhoods were at risk for a whole host of illnesses, from high blood pressure and diabetes to psychosis and depression.
In the study, which checked patients' records over a three-year period, 36 percent of men and 43 percent of women had diagnoses from the Elixhauser list, a list of comorbidities associated with worse health outcomes.
Depending on how poverty-stricken their neighborhood was, they also had slight differences in cumulative exposure to ionizing radiation from diagnostic imaging (CEDI). Mean CEDI values were about 10 millisieverts (plus or minus 19 mSv) for those in areas with greater than 10 percent poverty, and 8.9 mSv (plus or minus 22 mSv) in areas with less than 10 percent poverty. However, after controlling for increased comorbidities, among other factors, these differences largely vanished, the researchers said.
"Importantly, within each Elixhauser diagnosis group controlling for age and sex, (socioeconomic status) was no longer associated with CEDI," the doctors wrote in the paper.
In fact, after controlling for age, the only conditions for which links between Medicaid status or poverty and estimated CEDI were significant were chronic pulmonary disease and depression in men, and uncomplicated diabetes, complicated hypertension, fluid and electrolyte disorders and deficiency anemia in women, the authors said.
A few other differences popped up between men and women, too. For instance, being on Medicaid, but not the degree of poverty in the neighborhood, was linked to higher CEDI values for men, though the reverse was true for women: the degree of poverty in the neighborhood, but not being on Medicaid, was linked to higher CEDI.
The researchers noted the study does have some limitations. For instance, doses delivered by the scans were estimates, and not measured directly.
