The main reason for running clinical trials is to gain approval to sell a new drug or treatment. But clinical trials also present a chance for researchers to understand who will and who won’t benefit from a new drug, and—maybe more importantly—the experimental measures they test are a source of hope for patients who aren’t getting better on existing drugs. Unfortunately, new research shows, cancer treatment trials likely underrepresent low-income populations, raising concerns about the reliability of the data and the quality of care for an already vulnerable population.
It’s long been known that people low on the socioeconomic ladder aren’t as healthy as those who are financially better-off; a lack of insurance, limited access to doctors, and high costs conspire to keep low-income individuals from receiving the care they need. At the same time, it’s not uncommon for researchers to (consciously or unconsciously) exclude large swaths of the general population from their studies, which has significant consequences for the practice of medicine. Perhaps most famously, women continue to be dramatically underrepresented in studies of cardiovascular health and heart attacks, to the point where many doctors are unaware that men and women experience heart attacks differently.
The lower the income, the less likely patients were to opt for the latest, albeit experimental, treatments.
But while scientists know about gender and race disparities, “there hasn’t been much focus on socioeconomic status,” says Joseph Unger, a researcher at Fred Hutchinson Cancer Research Center in Seattle and lead author of the new research, which finds that patients with annual household incomes under $50,000 were 32 percent less likely to participate in clinical trials for new cancer treatments compared with higher-income patients. Those results confirm an earlier study Unger and his colleagues conducted using survey data collected after patients had undergone treatment.
For the new study, Unger and his team first contacted patients after they’d been diagnosed with breast, lung, or colorectal cancer, but before any treatment decisions had been made—a difference in method that could provide independent confirmation of their earlier findings. The researchers collected income data on a total of 1,262 patients, all of whom were eligible to participate in a clinical trial. They then stayed in touch with those participants for six months, in order to determine whether the patients subsequently took part in a clinical trial.
The result: Seventeen percent of those whose incomes topped $50,000 participated in trials, compared with 13 percent who made between $20,000 and $50,000, and 11 percent of those who made less than $20,000. The lower the income, the less likely patients were to opt for the latest, albeit experimental, treatments.
That’s not good for researchers or patients, Unger says. For researchers, it’s important to study low-income patients because they may not have the same access to follow-up care, and they’re probably not as healthy overall—two factors that could change a treatment’s chance of success.
For patients themselves, it’s a matter of having equal access to the latest medical advances. “It really should be a level playing field,” Unger says.
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