Randomized controlled trials for schizophrenia: study designs targeted to distinct goals

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

IMPORTANCE

Most evidence about efficacy and safety of antipsychotics in schizophrenia spectrum disorders relies on randomized clinical trials (RCTs). However, owing to their strict eligibility criteria, RCTs represent only a part of the real-world population (ie, unselected patients seen in everyday clinical practice), which may result in an efficacy-effectiveness gap.

OBJECTIVE

To quantify the proportion of real-world individuals with schizophrenia spectrum disorders who would be ineligible for participation in RCTs, and to explore whether clinical outcomes differ between eligible and ineligible individuals.

DESIGN, SETTING, AND PARTICIPANTS

This study applied eligibility criteria typically used in RCTs for relapse prevention in schizophrenia spectrum disorders to real-world populations. Individuals with diagnoses of schizophrenia spectrum disorders recorded in national patient registries in Finland and Sweden were identified. Individuals who had used antipsychotics continuously for 12 weeks in outpatient care were selected. Individuals were followed up for up to 1 year while they were receiving maintenance treatment with any second-generation antipsychotic (excluding clozapine). Follow-up was censored at treatment discontinuation, initiation of add-on antipsychotics, death, and end of database linkage.

MAIN OUTCOMES AND MEASURES

Proportions of RCT-ineligible individuals with schizophrenia spectrum disorders owing to any and specific RCT exclusion criteria. The risk of hospitalization due to psychosis within 1-year follow-up in ineligible vs eligible persons were compared using hazard ratios (HR) and corresponding 95% CIs.

RESULTS

The mean (SD) age in the Finnish cohort (n = 17 801) was 47.5 (13.8) years and 8972 (50.4%) were women; the mean (SD) age in the Swedish cohort (n = 7458) was 44.8 (12.5) years and 3344 (44.8%) were women. A total of 20 060 individuals (79%) with schizophrenia spectrum disorders would be ineligible for RCTs (Finnish cohort: 14 221 of 17 801 [79.9%]; Swedish cohort: 5839 of 7458 [78.3%]). Most frequent reasons for ineligibility were serious somatic comorbidities and concomitant antidepressant/mood stabilizer use. Risks of hospitalization due to psychosis was higher among ineligible than eligible individuals (Finnish cohort: 18.4% vs 17.2%; HR, 1.14 [95% CI, 1.04-1.24]; Swedish cohort: 20.1% vs 14.8%; HR, 1.47 [95% CI, 1.28-1.92]). The largest risks of hospitalization due to psychosis were observed in individuals ineligible owing to treatment resistance, tardive dyskinesia, and history of suicide attempts. Finally, with more ineligibility criteria met, larger risks of hospitalization due to psychosis were observed in both countries.

CONCLUSIONS AND RELEVANCE

RCTs may represent only about a fifth of real-world individuals with schizophrenia spectrum disorders. Underrepresented (ineligible) patients with schizophrenia spectrum disorders have moderately higher risks of admission due to psychosis while receiving maintenance treatment than RCT-eligible patients. These findings set the stage for future studies targeting real-world populations currently not represented by RCTs.

Real-World Data on the Adverse Metabolic Effects of Second-Generation Antipsychotics and Their Potential Determinants in Adult Patients: A Systematic Review of Population-Based Studies

INTRODUCTION

To assess the risk of occurrence and potential determinants of metabolic disorders in adult patients treated with second-generation antipsychotics (SGAs) under real-world practice conditions.

METHODS

MEDLINE, EMBASE, and PsycInfo were searched in July 2019 from database inception. We included population-based, longitudinal, comparative studies that report the results of the outcomes of interest for adult participants, including diabetes, ketoacidosis, hyperosmolar hyperglycemic state, weight gain/obesity, dyslipidemia, hypertension, and metabolic syndrome. Two reviewers independently extracted data on the study design, study quality, and study outcomes.

RESULTS

We included 40 studies. Most studies showed that clozapine and olanzapine were associated with an increased likelihood of developing diabetes, while the results for risperidone and quetiapine were mixed. Although less well studied, ziprasidone and aripiprazole appeared to not be associated with the occurrence of diabetes. Information on antipsychotic-induced weight gain/obesity is extremely scarce. Regarding dyslipidemia, aripiprazole was not associated with an increased likelihood of developing dyslipidemia, clozapine was associated with an increased likelihood of developing dyslipidemia, and risperidone, olanzapine, quetiapine, and ziprasidone showed mixed results. Two studies suggested an association between ziprasidone and the occurrence of hypertension. Several studies found that the occurrence of a metabolic disorder acted as a risk factor for the development of other metabolic disorders. We did not find information on brexpiprazole, cariprazine, or lurasidone, and data on any long-acting SGA were lacking.

CONCLUSION

Although there are relevant differences among SGAs concerning the risk of metabolic disorders, it appears that none of the SGAs included in our review are fully devoid of these disturbances.

The Representativeness of Participants With Severe Mental Illness in a Psychosocial Clinical Trial

Introduction: Cardiovascular morbidity and mortality are increased in severe mental illnesses (SMI). Trials of psychosocial health interventions to improve physical health in SMI, including in treatment-resistant schizophrenia, have shown some benefit. However, the representativeness of participants in such trials has not been determined. Method: We utilized an anonymised case register to determine if participants in a randomized controlled trial (RCT) of a novel psychosocial health intervention aiming to improve physical health in SMI had similar severity of illness to eligible non-participants. A retrospective database analysis was performed, using Health of the Nation Outcome Scale (HoNOS) data from the sample of patients participating in the IMPaCT (Improving Physical health and reducing substance use in Psychosis) RCT (n = 293) compared to all eligible participants with a psychotic illness (n = 774). Results: The mean total HoNOS score in the eligible comparator population (Mean = 9.09, SD = 5.8, range = 0-30) was significantly greater than that of the IMPaCT RCT participants (Mean = 7.16, SD = 4.7, range = 0-26), (t = 3.810, p = 0.006), as was the degree of overall illness severity and functional impairment, as measured by HoNOS. Conclusion: This study shows for the first time that the patient population participating in an RCT of a lifestyle intervention for those with SMI had a better mental health status at entry to the trial, than the total eligible population, although there was no difference in physical health needs. This has relevance to the applicability of RCTs of lifestyle interventions in service planning and suggests that when people are more unwell, greater effort may be needed to include them in psychosocial interventions. A more careful and focused recruitment approach should be followed to improve the participation of the more severely ill patients in psychosocial interventions in order to enhance the external validity of such studies.

Pragmatic design in randomized controlled trials

At more than 10 years after the paper by Hotopf and colleagues regarding pragmatic trials in psychiatry, the field has evolved and is evolving further. There have been many developments in our understanding of what pragmatism really means, and excellent examples of truly pragmatic trials in psychiatry are currently available. Funders have helped encourage more emphasis on the need for such studies, but 'local' and trans-national regulations could help more. Consumers of the evidence should have a greater voice in generating the research agenda and, as this happens, the questions generated are more likely to be answered by a pragmatic approach to trials.

Critical trial-related criteria in acute schizophrenia studies

The Trial Criteria in Schizophrenia Working Group was convened in November 2007 to define consensus criteria for clinical trials in patients suffering from acute schizophrenia with special focus on placebo-controlled trials and withdrawal conditions. Clinical trials involving patients give rise to ethical and medico-legal dilemmas. Essential research of new drugs may potentially expose patients to ineffective treatment regimens or placebo. The complexity of the problem increases when dealing with mentally ill patients. The Working Group's criteria are thought to cover different aspects important in conducting clinical trials namely to ensure the patient's safety, to present criteria that would allow the ethics committees to agree to the proposed criteria and to enable the possibility to reasonably conduct and ensure comparable quality of clinical studies in acutely ill patients with schizophrenia. To furthermore counteract current inconsistencies, these criteria should be evaluated using standardized rating scales applying established cut-off criteria. The developed trial criteria cover inclusion and exclusion criteria as well as withdrawal criteria due to non-response or worsening of symptoms.

Cost-effectiveness simulation analysis of schizophrenia at the Instituto Mexicano del Seguro Social: Assessment of typical and atypical antipsychotics

INTRODUCTION

Estimation of the economic costs of schizophrenia is a fundamental tool for a better understanding of the magnitude of this health problem. The aim of this study was to estimate the costs and effectiveness of five antipsychotic treatments (ziprasidone, olanzapine, risperidone, haloperidol and clozapine), which are included in the national formulary at the Instituto Mexicano del Seguro Social, through a simulation model.

METHODS

Type of economic evaluation: complete economic evaluation of cost-effectiveness.

STUDY PERSPECTIVE

direct medical costs.

TIME HORIZON

1 year. Effectiveness measure: number of months free of psychotic symptoms.

ANALYSIS

to estimate cost-effectiveness, a Markov model was constructed and a Monte Carlo simulation was carried out.

RESULTS

Effectiveness: the results of the Markov model showed that the antipsychotic with the highest number months free of psychotic symptoms was ziprasidone (mean 9.2 months). The median annual costs for patients using ziprasidone included in the hypothetical cohort was 194,766.6 Mexican pesos (MXP) (95% CI, 26,515.6-363,017.6 MXP), with an exchange rate of 1 € = 17.36 MXP. The highest costs in the probabilistic analysis were estimated for clozapine treatment (260,236.9 MXP).

CONCLUSIONS

Through a probabilistic analysis, ziprasidone showed the lowest costs and the highest number of months free of psychotic symptoms and was also the most costeffective antipsychotic observed in acceptability curves and net monetary benefits.