麻豆传媒

PHILADELPHIA -- Can informed consent work after study participation has taken place? Yes, under the right circumstances, researchers said Tuesday at the annual meeting of the American College of Emergency Physicians.

"There are significant barriers to obtaining informed consent in research studies specifically for acutely ill patients," said Abigail Mauermann, MS, a research coordinator at Massachusetts General Hospital in Boston. "This leads to inability to enroll [patients] early .... and in some cases, inability to enroll at all."

That, in turn, "may lead to cohorts that are less representative of our populations," she said. "There's also little literature comparing different methods of informed consent. So our hypothesis is that utilizing alternative procedures of informed consent can significantly increase the effectiveness of studies that are seeking to develop or validate novel diagnostic [products]."

To test their hypothesis, researchers used two different forms of informed consent as part of an ongoing study of adult patients at risk for bacteremia; these patients already needed blood draws as part of their diagnostic workup, and participating in the study involved getting some extra blood drawn.

In the first phase of the study, which lasted 18 months, the researchers used a standard informed consent procedure that involved getting the consent of the patient prior to drawing the blood needed for the study. In the second phase, which lasted 6 months, the researchers used an alternate method of informed consent, which involved drawing the blood as part of the initial blood draw, and then seeking consent from the patient to use the extra blood in the study.

In this case, the reason to get consent after the blood draw rather than before is that because these patients are so sick, they get treated with intravenous antibiotics right away, and -- if the researchers have to wait until after they explain the study and get the patient's consent -- the blood drawn at that point may look different than it would have if it had been drawn when the patient first came in, study coauthor Michael Filbin, MD, director of clinical research in emergency medicine at Massachusetts General Hospital, told 麻豆传媒.

"These are patients who are at risk for sepsis, so many of them are quite sick," he said. "And when they come through the door, the clinical team just descends upon them and starts getting them intravenous access, does the initial diagnostics, including the blood culture diagnostic, so there's really no time for a research assistant to interface with the patient, describe the research, the risks and benefits, and ask them if they'd like to participate. At that point, the blood's been drawn and the cultures have been sent." Instead, under the alternative protocol, "we're typically getting some consent for our sepsis patients several hours -- or an hour or two -- later."

Although it might seem surprising, getting such after-the-fact consent is legal under a federal regulation known as the . That law says exceptions to traditional informed consent may be employed as long as the risk to the patient is minimal, and as long as it's impractical to conduct the study any other way, "which, for a blood culture diagnostic, is a pretty strong case," said Filbin. The study protocol also received approval from an institutional review board, Mauermann said.

And while patients might be expected to be angry being asked for consent after the additional blood was already drawn, "very few people felt that way," said Mauermann. "We made sure we explained our reasoning for grabbing blood early in the process ... Overall, people were accepting of it."

Over the entire 24-month study period, the researchers approached 501 patients and got consent from 353 of them. The rate of patients consenting to be in the study increased from 53.5% of patients (159 out of 297) using traditional consent to 95.1% of patients (194 of 204) using after-the-fact consent.

And with the altered consent, "we were able to enroll older patients, more non-white patients, more patients with altered mental status, and overall higher acuity patients, which arguably is a lot more representative of our target population" of sepsis patients, said Mauermann.

"Alteration of informed consent definitely improved the effectiveness of a study that facilitates rapid development of novel diagnostics, because we were able to get really high consent rates," she said. "In the future, we would like to actually query patients about their satisfaction with these consent procedures. We have anecdotal evidence that overall there's really high satisfaction, and there's a high consent rate, but it would be nice to have concrete, formal data."

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