Study: subjects want chemical test results

When and how to release biomarker results is complicated issue for researchers, IRBs

Whether to return research results to participants is a thorny question, particularly in the field of environmental health research, which tests subjects' blood for substances such as metals or chemicals.

In the case of some environmental toxins such as lead and mercury, there is substantial evidence of their effects on the human body. So when reporting on lead levels, for example, a researcher can explain the impact of that level and recommend strategies for reducing exposure.

But the effects of many other chemicals on human health are currently unclear. Is it ethical to reveal a high level of a contaminant when scientists don't know the effect of it or how to minimize or treat exposure? Would it cause unnecessary anxiety to the participant to have this information?

The National Bioethics Advisory Commission has recommended disclosing individual test results to participants only when the findings are scientifically valid, the results have significant implications for a person's health and there's a readily available way to mitigate a person's exposure or treat any ill effects.

But when asked, participants say they want to know more, even in situations where the information is incomplete, says Stephen E. Wilson, MD, MSc, FACP, a volunteer assistant professor of internal medicine and pediatrics at the University of Cincinnati, OH.

'People want to know'

Wilson was an investigator in the Health Outcomes and Measures of the Environment (HOME) Study, a federally funded study that monitored environmental toxicants such as lead, mercury, pesticides, PCBs and tobacco smoke in pregnant women and children.

As part of that study, Wilson asked mothers hypothetically what their preferences would be for receiving information about pesticide residues, explaining to them that the health effects of low levels of exposure to these residues are currently unknown. Of the 343 mothers surveyed, 340 said that they would want to know their own levels and 342 would want to know those of their children.

"Based on our data it's clear – people want to know," Wilson says. "Even when you tell them you're not clear what these results mean, people clearly want to know and have a right to know."

The study also asked mothers about how they preferred that the information be relayed to them. Wilson says the survey provides some useful guidelines for researchers and IRBs contemplating disclosure of research results.

Overall, 69 percent of women said they would prefer to receive the results in a letter, with a phone number included that they could call if they had questions. However, women who had had no college education were more likely than others to ask for a face-to-face consultation instead with the investigator or with a woman's own doctor. The more college experience a woman had, the more likely she was to prefer a letter.

"I was surprised that so many people didn't want to receive the results in person," Wilson says.

While the survey didn't ask women the reasons for their preference, he noted that the group overall was somewhat more affluent and educated than average, and may be concerned about finding the time for an office visit. Wilson and his colleagues also suggest that more educated women may feel more confident in their ability to decipher the numbers themselves.

The women also were asked their preference regarding the format in which the information about the exposure should be given to them. The simplest format would be to provide an actual blood level statistic, with no comparisons to anyone in the study or national ranges for that chemical. The most complex would provide the same number, but would compare it to those in the study or national numbers. Sixty-nine percent wanted to receive the more complex information. But again, less educated mothers were more likely to ask for less complex formats.

Providing experts

Wilson says given the different preferences of different groups, researchers should be prepared to disclose results to participants in different ways.

"They should be specifically asking study participants how they want those results presented," he says.

And even if information is disclosed in letters, there should be experts ready to discuss the results with participants who have questions. For example, Wilson says, when his group disclosed results of tests that measured exposure to second-hand cigarette smoke, he got calls from some mothers concerned about their children's findings.

He explained to them that because the group being studied was less likely to live with smokers, a child in a mid-percentile in the study would still be in a fairly low percentile for the population as a whole.

And he says mothers trying to look up information about the results themselves on the Internet may find inaccurate and even frightening information. Wilson notes that a national network of Pediatric Environmental Health Specialty Units (PEHSUs) has developed scientifically validated fact sheets about various environmental exposures to help explain results to patients.

Wilson says it's important to keep studying what patients want to know about research results and how they want researchers to communicate with them.

"As we continue to see a growth in the use of biomarkers, it doesn't seem as if the ethics have caught up with the technology at this point," he says. "We need to study this more rigorously."


Wilson SE, Baker ER, Leonard AC, et al. Understanding preferences for disclosure of individual biomarker results among participants in a longitudinal birth cohort. J Med Ethics 2010 Dec;36(12):736-40.