People with schizophrenia who participate in clinical trials may not be representative of the population suffering from this disease.

• February 9, 2022
• Mireia Córcoles
• 1 comment

• An international study led by I3PT notes that clinical trials may account for only about one-fifth of people in the real world with schizophrenia spectrum disorders, and points out that new studies should be promoted. aimed at the real world population, which is currently underrepresented.

Clinical trials on the effectiveness of treatments for schizophrenia have a number of criteria for excluding patients, such as the presence of severe somatic comorbidity or the concomitant use of antidepressants. One new international research in which they have participated August Pi i Sunyer Biomedical Research Institute (IDIBAPS) / Hospital Clínic of Barcelona,Parc Taulí Research and Innovation Institute (I3PT), and the CIBER Mental Health (CIBERSAM) shows that the people with schizophrenia who are not eligible for clinical trials have an increased risk of hospitalization. That makes that people with schizophrenia who participate in clinical trials may not be representative of the population suffering from this disease.

The study, published in JAMA Psychiatry - the world's number 3 in psychiatry - quantified the proportion of people in the real world with schizophrenia spectrum disorders who would not be eligible to participate in a clinical trial, and identified whether the risk of hospitalization differed. between eligible and ineligible people. The result was a significant difference between clinical evolution in clinical trials (related to efficiency) and in routine clinical practice (related to effectiveness), which it has been called the gap between effectiveness and efficiency.

To understand how the criteria for inclusion and exclusion in clinical trials affect the results, the authors, including Just Pinzón Espinosa, co-principal investigator of the study, the Cardoner Narcís, researchers from I3PT and CYBERSAM –Belonging to the group led by Diego José Palao–, and Joaquim Radua, Luis Pintor and Eduard Vieta from IDIBAPS and Hospital Clínic –CIBERSAM researchers belonging to the group coordinated by Dr. Vieta–, applied these criteria to real-world populations. Specifically, they identified all people with schizophrenia from the national registries of Finland and Sweden, selected the 25.259 who had received antipsychotics continuously for 12 weeks in outpatient care, and followed them (in the records) for a year, emulating the treatment and follow-up performed in a clinical trial.

The researchers found that the fact that almost 80% of people with schizophrenia would not have been eligible for a clinical trial, especially due to severe somatic comorbidity and concomitant use of antidepressants or mood stabilizers.. This majority of patients showed an increased risk of hospitalization for psychosis (hazard ratio of 1,14-1,47). The highest risk was observed in people with the highest number of ineligibility criteria, highlighting treatment resistance, late dyskinesia, and a history of suicide attempts.

"Clinical trials can account for only about one-fifth of real-world people with schizophrenia spectrum disorders”, As described by the authors. They also emphasize that "ineligible people have a moderately higher risk of admission due to psychosis." These results indicate that Patients participating in clinical trials tend to be less severe than those seen in a purely healthcare setting., the that new studies aimed at the real world population should be promoted, which is currently not well represented in clinical trials.

Article reference:

Representation and Outcomes of Individuals With Schizophrenia Seen in Everyday Practice Who Are Ineligible for Randomized Clinical Trials

JAMA Psychiatry. 2022 Jan 26. doi: 10.1001 / jamapsychiatry.2021.3990.