Generalizability of the results of efficacy trials in first-episode schizophrenia: Comparisons between subgroups of participants of the European First Episode Schizophrenia Trial (EUFEST)

Abstract

Objective: Most randomized drug trials in schizophrenia exclude patients with comorbidities such as suicidality or substance use, which may limit the generalizability of the results. We aimed to evaluate the generalizability of the results of these trials in participants of a randomized clinical trial with broad inclusion criteria. Method: In 50 sites in 14 countries, 498 patients with first-episode psychosis (DSM-IV schizophrenia, schizoaffective disorder, or schizophreniform disorder) were recruited between December 2002 and January 2006 in an open, randomized clinical drug trial with 12 months of follow-up. Baseline characteristics and follow-up data were compared between patients with versus patients without baseline suicidality and/or substance use. Results: Of the 489 participants with data on baseline suicidality and substance use, 153 (31%) patients were suicidal and/or using substances. Groups differed on only a few of the many baseline characteristics tested: comorbid patients were younger (25.1 vs 26.5 years of age; P < .01), less often female (25% vs 47%; P < .001) or married (4% vs 17%; P < .001), had fewer years of education (11.8 vs 12.8; P < .001), and experienced lower levels of overall psychosocial functioning (Global Assessment of Functioning; 38.4 vs 40.8; P ≤ .05) and higher levels of depression (Calgary Depression Scale for Schizophrenia; 6.1 vs 4.6; P