'Informed' ICU Patients Forget Clinical Trial Details

GENEVA, Dec. 7 -- Patients in the intensive care unit who give informed consent to participate in a clinical trial may not truly capable of making such a decision, according to a small study.

Among 44 competent patients enrolled in a trial after admittance to the ICU, 80% recalled being in a clinical trial about 10 days later but only 32% knew the purpose and its risks, said Catherine Chenaud, M.D., of the University Hospital of Geneva, and colleagues.

These findings, published online Dec. 7 in the journal Critical Care, call into question current recruitment practices for ICU patients, the investigators said. Informed consent requires complete disclosure of risks and benefits, the patient's comprehension, and voluntary participation.

"However, if the clinical trial has already begun and the patient is unaware of the purpose, related risks, and their participation in the clinical trial," the authors wrote, "they are obviously unable to decide mindfully whether to continue in the clinical trial or to withdraw from it at any time."

A good indication that the patient will remember the purpose and risks associated with the trial is their participation in the conversation initially. The researchers found:

• Complete recall of both risks and purpose of the trial was significantly more common among patients who asked at least one question (P=0.03),
• 93% of patients with complete recall, compared with 60% with incomplete recall, had read a one-page informational leaflet about the trial or asked at least one question before signing the consent form (13 of 14 versus 18 of 30, P=0.03).

The researchers suggested that informed consent should be viewed as a process rather than a procedure.

"The informed consent process requires, to our mind, multiple conversations on several occasions while the research is conducted," they wrote.

The study was performed under the auspices of a larger clinical trial about inflammation. The researchers approached patients admitted to the ICU after a major surgery or trauma with a Glasgow Coma Score of 15, who were not on mechanical ventilation, were fully oriented, and were judged competent by the investigator and attending physician.

The researchers then individually gave patients, a 20-minute oral presentation, per protocol, and one-page leaflet about the trial emphasizing the purpose and risks. Patients were told that the risk was minimal and that the trial would require drawing 10 ml of blood for the first five days of their stay and then at day 28. Patients signed informed consent forms.

Ten to 12 days later, the investigator returned to interview the patient on recall and to arrange for the visit on day 28. The researchers found:

• 35 of the 44 patients remembered participating in the trial.
• 20 of the 44 patients could recall the purpose of the study.
• 21 of the 44 patients retained a memory of the study risks.
• 14 of the 44 remembered both the purpose and associated risks of the trial.

Patients with complete recall were similar to those with incomplete recall in demographics, education, admission characteristics, duration of mechanical ventilation, ICU stay, and medications administered during the 24 hours before and after giving informed consent.

These findings were similar to a previous study by the same group in which informed consent was obtained before ICU admission (22% did not recall participation in the trial compared to 20% in the current study).

However, only 25% of patients in the pre-ICU informed consent study forgot the trial purpose and related risks compared to 68% of patients approached during ICU stay.

"The low rate of complete recall in the present study could be explained by the difficulty of some ICU patients to process information given the stress of the acute phase and possibly experiencing feelings of dependence and anguish," Dr. Chenaud and colleagues wrote.

Because the study included only a specific group of relatively well patients in the ICU, the results may not be generalizable to the majority of ICU patients.

"However, it is reasonable to speculate that the rate of recall may be even worse in usual patients in the ICU," the investigators added.

The study was limited by the small sample size and that there was no data on recall of patients who had refused to participate in the trial.

Nonetheless, the researchers suggested that investigators repeatedly repeat clinical trial information to participants while the research is being conducted and even after discharge from the ICU.

The authors reported no financial disclosures.