Lower-income patients less likely to be in cancer trials

Survey shows less participation

A survey of nearly 5,500 cancer patients found that those with lower incomes were less likely to be enrolled in clinical trials, and more likely to be concerned about paying for participation in a trial.

Even when accounting for factors such as education, minority status and co-morbidity status, patients with annual household incomes of less than $50,000 were less likely to be enrolled in a trial than those with an income of $50,000 or more.

The findings held true even for patients over 65, who have access to Medicare, says Joseph Unger, MS, PhC, a statistician and health services researcher at the Fred Hutchinson Cancer Research Center in Seattle. Unger is also on the staff of the Statistical Center at the SWOG cancer research cooperative group, which conducted the survey.

"The results may point to a generalized anxiety about how to pay for things, especially when you're dealing with clinical trial participation, about which patients may already feel uncertainty," Unger says. "The additional uncertainty about what it would cost may make it particularly difficult for lower-income patients to decide that a clinical trial might be for them."

In a statistical model accounting for demographic, socioeconomic and co-morbidity factors, patients with incomes less than $50,000 per year were 27% less likely to participate in clinical trials, compared to higher-income patients. When income level was split at $20,000 per year, patients with lower incomes were 44% less likely to participate.

In the end, income level was the only socioeconomic or demographic factor that remained an independent predictor of clinical trial participation, Unger says. "That was a bit of a surprise."

Unger's group presented their findings in June at the annual meeting of the American Society for Clinical Oncology.

He says that the study results raise concern that clinical trials, an important patient resource for state-of-the-art-therapies, are not equally accessible to patients of all income levels. He says participation by lower-income patients in the trials would make trial results more generalizable and would allow trials to be conducted more quickly.

In examining the data about trial participation, researchers were careful to separate income from other factors, including education and co-morbidity. Unger says patients sometimes have medical conditions in addition to cancer that may make them ineligible to participate in clinical trials.

"Those who have lower socioeconomic status have been shown to have higher rates of conditions such as diabetes or high blood pressure, which could lead them to be ineligible for trials based on that factor alone," he says.

He notes research has shown that the health care costs to patients participating in a trial are not appreciably higher than costs for standard clinical care.

"But patients may still be concerned about co-pays and co-insurance, even if they're not necessarily higher than for non-trial care," Unger says, noting that better communication in the informed consent may help alleviate those concerns.

"There's been some suggestion that consent forms are not very clear about what costs are covered for patients in a clinical trial," he says. "If that is true, then greater clarity in consents could help patients better understand the cost burdens of participation and whether there is an extra burden at all."

He also says that indirect costs of participation — things like transportation and time off from work — may factor into a lower-income patient's decision. Helping relieve those costs could be a step toward lessening the burden on patients.

"Simple things like free bus passes and paid parking could make participation more convenient, especially for lower-income patients," Unger says. "Flexible clinic hours, to allow patients greater convenience, regardless of what type of work they have, might also encourage participation."