Competency tool not excessively burdensome

Use of subject advocates not as effective

Investigators who used a competence assessment tool as part of a large clinical study of antipsychotic drugs and a schizophrenia population have found that the tool’s use during the study’s informed consent process was not considered burdensome by most clinical trial staff and investigators.

"We took a relatively new instrument that had been used on a small scale, and we used it on a large scale study," says Scott Stroup, MD, MPH, an associate professor of psychiatry at the University of North Carolina at Chapel Hill. Stroup presented a poster about the tool’s use in the study at the 2005 annual conference of the Public Responsibility In Medicine & Research (PRIM&R), held Dec. 3-6 in Boston.

Thirty percent of investigators said using the tool posed a significant burden on research staff, but most did not agree, Stroup says.

The study, sponsored by the National Institutes of Mental Health,was designed to compare the effectiveness of antipsychotic drugs over the long term, and it was begun in 1999, Stroup explains.

The main article was published in the New England Journal of Medicine in September 2005. "When we started the study there was a lot of controversy in the news and elsewhere about schizophrenia research," Stroup says.

A report by the National Bioethics Advisory Commission had suggested that people who have the potential for decision-making impairments should have their decision-making competence assessed independently prior to their inclusion in a trial, Stroup says.

Some psychiatric researchers felt this would be discriminatory toward certain subject populations and that it would be a significant burden and impediment to research, he adds.

One possible way to address some of the concerns about the report is to use a competency-assessment tool to assess subject’s ability to provide informed consent. So investigators involved in the schizophrenia trial used the MacArthur Competence Assessment Tool-Clinical Research (MacCAT-CR) during the informed consent process. It took about 20 minutes to administer, although when first used it took up to 45 minutes, he says.

They found that using the instrument during a large-scale clinical trial was feasible, and it didn’t greatly burden the sites or impede enrollment in the study, Stroup says.

Clinicians, research nurses, and clinical social workers administered the instrument and informed consent process, he says.

"Our evaluation showed that some people found it to be a very useful tool in assessing capacity and getting informed consent," Stroup says. "But if the goal of it was to screen out people who were incompetent, it really wasn’t necessary."

Investigators found that fewer than 5% of subjects were screened out from the study due to the MacCAT-CR, Stroup says. "That doesn’t mean that fewer than 5% of people with schizophrenia have substantial impairment, but only a small percentage of people the researchers thought would be ready for the trial were impaired in their decision-making capacity," he explains. "So my interpretation is that investigators pre-screened pretty well for the people who were able to understand the consent process and who would understand the research."

Since investigators didn’t know what the cut-off point would be on the MacCAT-CR, they used the instrument with a low threshold score, leaving the final decision up to the physician, Stroup says. "We didn’t want to set an arbitrarily high threshold that would keep people out of the study," he says. "But what we found was that a lot of people were way above the threshold we established."

Another investigator, Scott Kim, MD, PhD, at the University of Michigan in Ann Arbor is using the study’s data to try to determine an appropriate cut-off point with the instrument, Stroup notes. "That’s one spin-off from this project," he says. "Another thing is we used the instrument throughout the study, so if someone discontinued treatment, we used the MacCAT-CR, as well."

Once longitudinal data from the instrument’s use are analyzed researchers will know if there were significant fluctuations in subjects’ capacity during the trial, Stroup says.

The study also involved another informed consent innovation: use of a subject advocate, Stroup says. "Our subject advocate procedures could use some improvement," Stroup says. "Ideally, we asked people to designate a family member or friend or caregiver or case manager as their advocate."

However, with a schizophrenia population, there may not be many people in their social network, so the study also had to assist subjects find volunteer advocates, he says.

"We had to find other people who weren’t part of the research project who could pinch hit and fill in," Stroup says. "In some places they found people from local advocacy groups to serve as subject advocates, and others might have a case manager who worked at their agency but who wasn’t involved in the research."

Research subject advocates were expected to be present during the consent process and to understand the subject’s motivation for participating in the trial, he says.

Advocates also were expected to understand the risks and benefits, so if the subject’s capacity lapsed, they could be consulted by investigators, Stroup notes.

"If investigators were concerned about a lapse in decision-making capacity, or if they felt like there had been a lapse in capacity, they could check with the advocate to make sure it was reasonable to keep the person in the study," Stroup says.

A study of the use of the research subject advocates found that only a third of respondents thought the use of advocates had aided retention in the study, and most thought there had been no effect.1 More than a third of respondents thought the use of advocates had a positive effect on subject autonomy, but, again, most found no discernible effect.

The study also revealed that almost no respondents found that the use of subject advocates had any negative effects on subjects’ rights or retention.

"Some people liked using subject advocates because it helped to engage family members and others into the study, and it reassured subjects that someone else was looking out for them," Stroup says. "It reassured investigators that other people were involved in the study, and participation was reasonable."

Also, IRBs tended to like the study having research advocates, and advocacy groups liked it, so there were collateral benefits, Stroup notes.


  1. Stroup TS, Appelbaum PS. Evaluation of "subject advocate" procedures in the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) schizophrenia study. Schizophrenia Bulletin. 2006 Jan;32(1):147-152.