Cancer patients with lower incomes are a third less likely to be part of clinical trials that could help treat their disease than those whose annual income is at least $50,000, according to a new study. Researchers suggest that covering some of the costs of participating in a research study might enhance enrollment.

Clinical trials, which test new treatments or prevention methods to determine whether they are safe and effective, are an essential component of medical research. Yet only a small percentage of eligible patients participate in them.

One of the main reasons clinical trials fail is because they don’t get enough people to enroll. If the number of patients who participate could be doubled or quadrupled, many more trials could be completed, says Joseph Unger, biostatistician and health services researcher in cancer clinical trials at the Fred Hutchinson Cancer Research Center in Seattle.

Unger and colleagues examined the association between income and clinical trial participation in 1,262 patients at eight cancer clinics during the six months following their initial diagnosis or recurrence of breast, colorectal or lung cancer. Their research letter, which was published in JAMA Oncology this month, found 17 percent of those whose annual household incomes were $50,000 or higher participated in clinical trials, compared with 12 percent of those with incomes below that threshold.

The clinical trial will often cover the costs of the research treatment or procedure. But there are generally other costs involved too. Even though most health plans and Medicare are required to pay for routine costs that could arise such as drugs, procedures and services that insurance would normally cover, patients may still be on the hook for copayments or coinsurance for those drugs and services, as well as travel and lost wages, among other things.

“Those marginal costs could still be a barrier” for lower income patients, Unger says.

Unger suggests that patients could be reimbursed for the extra costs of clinical trial participation, as long as care is taken to ensure financial inducements don’t have the effect of strong-arming patients into trials. Some trials currently offer financial incentives, but the practice is haphazard, Unger says.

As for patients with cancer, “If trials provide the newest treatments, there shouldn’t be anything getting in the way of patients getting access to those treatments,” says Unger.

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