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Stick to the statistics on risk in informed consent documents
Researcher says numbers aren't subjective
IRB members, investigators, and others sometimes believe that potential trial participants will find hard data and numbers confusing when reading these as descriptions of risk in informed consent documents.
They think using numbers will scare away people, but this is a misguided notion, according to a biostatistician.
"I don't buy that argument because people use numbers all the time," says Yen-Hong Kuo, ScN, MS, a PhD-candidate and biostatistician at the Jersey Shore University Medical Center in Neptune, NJ.
"My opinion is you present both," Kuo says.
Investigators should put in the IC document both the statistics related to possible risks and descriptions or characterizations of that risk, he suggests.
"It's a very simple idea because there's nothing wrong with presenting both, especially since risk is a key component for them to make that decision," he says. "As long as it's your principle to be informative, then you can provide the best possible information for people to know."
This way, if a person reading the IC document doesn't like seeing numbers in it, they can read the explanation and make their decision based on that part, he adds.
"Or if they like the numbers, then they can see it right away instead of having to ask for more information," Kuo says.
For example, in a phase III study, the sponsor might have data showing that 10% of people receiving treatment experience hair loss, Kuo says.
The informed consent document could be worded to say that hair loss has been common in this study, and it is experienced by about 10% of people taking this drug, he adds.
IRBs might insist on characterizations of risk, such as describing a risk as rare, common, minor, moderate, or serious.
If investigators choose to classify the risk, that is their choice, but they should keep it simple and clear-cut and put the percentage next to the classification, as well, he says.
"Describe it in a way that people might read it, but put in the word and percentage side-by-side," he says. "A number is a number and does not change, and people know what percentage means."
Investigators also could translate percentages, saying perhaps that one person in 100 might experience a stroke, instead of just saying the risk of having a stroke is 1%, abut Kuo doesn't believe this is necessary.
People commonly read nutritional statistics now, and they're aware of the odds listed when they buy lottery tickets, Kuo says.
"So I feel strongly that we might overprotect our subjects," he says. "Percentages are a common way to communicate," he adds.
"The point I emphasize is the perception of the subject may be different from the perception of the researcher," Kuo says. "If you give a number that is a 1% risk and you call it a 'rare'risk, the subject might feel like 1% is a high risk."
So if the investigator omitted the number and just used the term "rare," he or she might be giving the potential subject information that seems inaccurate to them, and so there is a discrepancy, he explains.
"But if you say the risk is a 1% risk, then it's clear information, and it's the same no matter how it's worded, and subjects can make their own decisions based on it," he adds.
The best way to handle descriptions of risk is to put in the percentages and then have the investigator spend time with potential participants, describing what the number represents, Kuo says.
"If subjects feel like they have no idea about what 1% means, then the investigator can provide that kind of help," Kuo says.
"If we used some other words to translate every percentage you use in the informed consent, then you'll make the document much longer than planned," he explains. "The researcher should be responsible and explain to the subject what it means and answer any questions the person has."
When dealing with studies where there are no data and percentages related to risk, the informed consent document should say the risks are unknown, Kuo says.
"You could say, 'We're going to study what the risk will be, so we don't have data yet,'" he suggests.