ArticleThe British journal of psychiatry : the journal of mental science2023
Clinical impact of reducing the frequency of clozapine monitoring: controlled mirror-image cohort study.
Article in The British journal of psychiatry : the journal of mental science, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers.
What it found
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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.
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Who cites it
9 citing papers in PubMed, 24 citations in OpenAlex.
- Late-Onset Neutropenia in Clozapine Users: Unrelated or Drug-Induced? A Case-Registry Analysis of Incidence, Characteristics, and Rechallenge Attempts.Schizophrenia bulletin · 2026Article
- Treating Unmet Needs in Psychiatry (TUNE-UP): targeted service increases out-patient initiations of clozapine.BJPsych open · 2026Article
- Discontinuation of the Clozapine Risk Evaluation and Mitigation Strategy and Implications in Movement Disorders.Movement disorders clinical practice · 2025Article
- Low awareness of clozapine-induced agranulocytosis in a mixed-method survey of 354 patients and carers.Schizophrenia (Heidelberg, Germany) · 2025Article
- A Call to Action for Starting Clozapine: Increasing Clozapine Use and Safety in a Post-REMS Era.Focus (American Psychiatric Publishing) · 2025Review
- The Safety of 12-Weekly Monitoring of Neutrophil Count in Long-Term Clozapine Patients.Acta psychiatrica Scandinavica · 2025Observational
- Anti-Suicidal Effects of Lithium, Ketamine, and Clozapine-A 10-Year Systematic Review.Pharmaceuticals (Basel, Switzerland) · 2025Review
- Evaluating Reduced Blood Monitoring Frequency and the Detection of Hematological Abnormalities in Clozapine-Treated Patients With Schizophrenia: A Chart Review Study From the COVID-19 Pandemic.Schizophrenia bulletin · 2025Article
- Letter to the FDA Proposing Major Changes in the US Clozapine Package Insert Supported by Clozapine Experts Worldwide. Part II: A Review of Fatal Outcomes in US Pharmacovigilance Data and Proposed Changes.Journal of clinical psychopharmacologyArticle
Corrections and comments
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Authors and funding
12 authors at 5 institutions in 1 country.
Funding
Abstract
backgroundTo minimise infection during COVID-19, the clozapine haematological monitoring interval was extended from 4-weekly to 12-weekly intervals in South London and Maudsley NHS Foundation Trust.
aimsTo investigate the impact of this temporary policy change on clinical and safety outcomes.
methodAll patients who received clozapine treatment with extended (12-weekly) monitoring in a large London National Health Service trust were included in a 1-year mirror-image study. A comparison group was selected with standard monitoring. The proportion of participants with mild to severe neutropenia and the proportion of participants attending the emergency department for clozapine-induced severe neutropenia treatment during the follow-up period were compared. Psychiatric hospital admission rates, clozapine dose and concomitant psychotropic medication in the 1 year before and the 1 year after extended monitoring were compared. All-cause clozapine discontinuation at 1-year follow-up was examined.
resultsOf 569 participants, 459 received clozapine with extended monitoring and 110 controls continued as normal. The total person-years were 458 in the intervention group and 109 in the control group, with a median follow-up time of 1 year in both groups. During follow-up, two participants (0.4%) recorded mild to moderate neutropenia in the intervention group and one (0.9%) in the control group. There was no difference in the incidence of haematological events between the two groups (IRR = 0.48, 95% CI 0.02-28.15,
conclusionsThere was no evidence that the incidence of severe neutropenia was increased in those receiving extended monitoring.
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