Evidence map›Paper›PMID 36810167›Full record

ArticleBMJ open2023

Efficacy of clozapine compared with other second-generation antipsychotic drugs in patients with treatment-resistant schizophrenia: protocol for a systematic review and individual patient data meta-analysis of randomised controlled trials.

Spyridon Siafis, Johannes Schneider-Thoma, Tasnim Hamza, Irene Bighelli, Shimeng Dong, Wulf-Peter Hansen, John M Davis, Georgia Salanti, Stefan Leucht

Abstract read
In one paragraph

Article in BMJ open, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors.

Spyridon SiafisDepartment of Psychiatry and Psychotherapy, School of Medicine, Technical University of Munich, Munich, Germany.ORCID 0000-0001-8264-2039
Johannes Schneider-ThomaDepartment of Psychiatry and Psychotherapy, School of Medicine, Technical University of Munich, Munich, Germany joh.schneider@tum.de.ORCID 0000-0002-3448-9532
Tasnim HamzaInstitute of Social and Preventive Medicine, University of Bern, Bern, Switzerland.ORCID 0000-0002-4700-6990
Irene BighelliDepartment of Psychiatry and Psychotherapy, School of Medicine, Technical University of Munich, Munich, Germany.ORCID 0000-0002-5661-5149
Shimeng DongDepartment of Psychiatry and Psychotherapy, School of Medicine, Technical University of Munich, Munich, Germany.ORCID 0000-0002-8095-0545
Wulf-Peter HansenBASTA - Bündnis für psychisch erkrankte Menschen, Munich, Germany.
John M DavisPsychiatric Institute, University of Illinois at Chicago, Chicago, Illinois, USA.
Georgia SalantiInstitute of Social and Preventive Medicine, University of Bern, Bern, Switzerland.ORCID 0000-0002-3830-8508
Stefan LeuchtDepartment of Psychiatry and Psychotherapy, School of Medicine, Technical University of Munich, Munich, Germany.ORCID 0000-0002-4934-4352

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionGuidelines recommend clozapine for treatment-resistant schizophrenia. However, meta-analysis of aggregate data (AD) did not demonstrate higher efficacy of clozapine compared with other second-generation antipsychotics but found substantial heterogeneity between trials and variation between participants in treatment effects. Therefore, we will conduct an individual participant data (IPD) meta-analysis to estimate the efficacy of clozapine compared with other second-generation antipsychotics while accounting for potentially important effect modifiers. METHODS AND ANALYSIS: In a systematic review, two reviewers will independently search Cochrane Schizophrenia Group's trial register (without restrictions in date, language or state of publication) and related reviews. We will include randomised controlled trials (RCTs) in participants with treatment-resistant schizophrenia comparing clozapine with other second-generation antipsychotics for at least 6 weeks. We will apply no restrictions in age, gender, origin, ethnicity or setting, but exclude open-label studies, studies from China, experimental studies and phase II of cross-over trials. IPD will be requested from trial authors and cross-check against published results. AD will be extracted in duplicate. Risk of bias will be assessed using Cochrane's Risk of Bias 2 tool.The primary outcome will be overall symptoms of schizophrenia.We will synthesise results using random-effects meta-analysis and meta-regression methods in a 3-level Bayesian model. The model combines IPD with AD when IPD is not available for all studies, and include participant, intervention and study design characteristics as potential effect modifiers. The effect size measures will be mean difference (or standardised mean difference when different scales were used). Confidence in the evidence will be assessed using GRADE. ETHICS AND DISSEMINATION: This project has been approved by the ethics commission of the Technical University of Munich (#612/21 S-NP). The results will be published open-access in a peer-review journal and a plain-language version of the results will be disseminated.If we need to amend this protocol, we will describe the change and give the rationale in a specific section in the resulting publication 'Changes with respect to the protocol'. SYSTEMATIC REVIEW REGISTRATION: PROSPERO (#CRD42021254986).

Indexed as

Antipsychotic AgentsClozapineSchizophreniaHumansMeta-Analysis as TopicPatientsSchizophrenia, Treatment-ResistantSystematic Reviews as TopicAntipsychotic AgentsClozapineadult psychiatrymental healthschizophrenia & psychotic disorders

Identifiers

PMID36810167
PMCPMC9945033

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.