Geographical and temporal variations in clozapine prescription for schizophrenia

Nielsen, Jimmi; Røge, Rasmus; Schjerning, Ole; Sørensen, Holger J.; Taylor, David

doi:10.1016/j.euroneuro.2012.03.003

Cited by 75 publications

(69 citation statements)

References 30 publications

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“…Previous studies have reported geographical differences in use of antipsychotics, but aimed at investigating the use in the general population or in patients with schizophrenia [25][26][27]. In accordance with our study, a study from the U.S. found local geographical variation in the use of antipsychotics that by far exceeded the observed variability between states in the general population of all ages [25].…”

Section: Discussionsupporting

confidence: 76%

Geographical Variation in Antipsychotic Drug Use in Elderly Patients with Dementia: A Nationwide Study

Zakarias

Jensen‐Dahm

Nørgaard

et al. 2016

JAD

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Abstract.Background: Use of antipsychotics in elderly patients with dementia has decreased in the past decade due to safety regulations; however use is still high. Geographical variation may indicate discrepancies in clinical practice and lack of adherence to evidence-based guidelines for the management of behavioral symptoms. Objective: To investigate potential geographical variances in use of antipsychotic drugs in dementia care. Methods: A registry-based cross-sectional study in the entire elderly population of Denmark (≥65 years) conducted in 2012. Data included place of residence, prescriptions filled, and hospital discharge diagnoses. Antipsychotic drug use among elderly with (n = 34,536) and without (n = 931,203) a dementia diagnosis was compared across the five regions and 98 municipalities in Denmark, adjusted for age and sex. Results: In 2012, the national prevalence of antipsychotic drug use was 20.7% for elderly patients with dementia, with a national incidence of 3.9%. The prevalence ranged from 17.0% to 23.3% in the five regions and from 7.5% to 33.1% in the 98 municipalities, demonstrating an over four-fold difference. Conclusion: The observed geographical variation was more pronounced at municipal level as compared to regional level, suggesting that the variation may be related to variances in clinical practice in primary care. This study highlights an urgent need for further educating professional carers and physicians to guide non-pharmacological as well as pharmacological management of neuropsychiatric symptoms in elderly patients with dementia.

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Section: Discussionsupporting

confidence: 76%

Geographical Variation in Antipsychotic Drug Use in Elderly Patients with Dementia: A Nationwide Study

Zakarias

Jensen‐Dahm

Nørgaard

et al. 2016

JAD

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“…The same study reported a higher mean clozapine dose in the USA of 444 mg daily. In a recent study by Nielsen and colleagues the mean clozapine dose in a Danish cohort was reported to be 382 mg (10). In a small Swedish cohort (n ¼ 33) the clozapine NORDIC JOURNAL OF PSYCHIATRYdose was recently reported to be somewhat higher at 460 mg, and closer to doses seen in the USA (22).…”

Section: Discussionmentioning

confidence: 99%

“…Clozapine use in schizophrenia varies widely between countries: from being as high as 26.9% (8) in Taiwan, 26.7% in China (8), 15.2% in Australia (9), 10.1% in Denmark (10), to as low as 4.4% in the USA (11). It is not well understood why clozapine appears underutilized in some countries despite the strong evidence for its efficacy in treatment-resistant schizophrenia.…”

mentioning

confidence: 99%

Clozapine treatment and discontinuation in Iceland: A national longitudinal study using electronic patient records

Ingimarsson

MacCabe

Jónsdóttir

et al. 2016

Nordic Journal of Psychiatry

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Background: Clozapine is the only drug approved for treatment-resistant schizophrenia. There is evidence that clozapine is underutilized. Aims: To evaluate the initiation and discontinuation of clozapine at Landspitali University Hospital in Iceland and the prevalence of antipsychotic polypharmacy in clozapine-treated patients. Methods: The study is a part of an ongoing longitudinal study of schizophrenia in Iceland. We identified 201 patients on clozapine or who have been on clozapine by using a keyword search in the electronic health records and by reviewing their medical records. Results: Mean age at first treatment with clozapine was 37.8 years. Mean follow-up period on clozapine was 11 years. After 20 years of treatment 71.2% of patients were still on clozapine. After one year of treatment 84.4% of patients were still receiving clozapine treatment. We estimate that 11.4% of patients with schizophrenia in Iceland are taking clozapine and that 16% have been treated with clozapine at some point. Polypharmacy is common, since nearly 2/3, 65.6%, of patients taking clozapine use at least one other antipsychotic and 16.9% are also receiving depot injections. Conclusions: We need to increase the awareness of psychiatrists in Iceland with regard to treatment with clozapine, since only about half of the estimated population of patients with treatment-resistant schizophrenia in Iceland have ever been treated with clozapine. Nearly two thirds of patients who are prescribed clozapine in Iceland remain on it long-term.

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“…Previous studies investigating risk factors for TR have utilised clozapine prescription rates as a proxy measure of TR ( (Nielsen et al, 2012b, Schneider et al, 2015, Stroup et al, 2014, however, given the underutilisation of clozapine in clinical practice, such studies do not measure all people with TR. Although, a few potential risk factors for treatment resistance (TR), such as poor premorbid functioning, living in less urban areas, comorbid personality disorder, longer duration of untreated psychosis (DUP), greater severity of negative symptoms, and a younger age of illness onset have been suggested (Frank et al, 2015, Martin and Mowry, 2016, Meltzer, 1997, Ortiz et al, 2013, Schennach et al, 2012, Vanelle et al, 1994, Wimberley et al, 2016, the predictive value of specific clinical and demographic factors on treatment resistance in first episode schizophrenia has not yet been widely investigated (Lin et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Two distinct patterns of treatment resistance: clinical predictors of treatment resistance in first-episode schizophrenia spectrum psychoses

et al. 2016

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BackgroundClozapine remains the only evidence-based antipsychotic for treatment-resistant schizophrenia (TRS). The ability to predict which patients with their first onset of schizophrenia would subsequently meet criteria for treatment resistance (TR) could help to diminish the severe functional disability which may ensue if TR is not recognized and correctly treated.MethodThis is a 5-year longitudinal assessment of clinical outcomes in a cohort of 246 first-episode schizophrenia spectrum patients recruited as part of the NIHR Genetics and Psychosis (GAP) study conducted in South London from 2005 to 2010. We examined the relationship between baseline demographic and clinical measures and the emergence of TR. TR status was determined from a review of electronic case records. We assessed for associations with early-, and late-onset TR, and non-TR, and differences between those TR patients treated with clozapine and those who were not.ResultsSeventy per cent (n = 56) of TR patients, and 23% of the total study population (n = 246) were treatment resistant from illness onset. Those who met criteria for TR during the first 5 years of illness were more likely to have an early age of first contact for psychosis (<20 years) [odds ratio (OR) 2.49, 95% confidence interval (CI) 1.25–4.94] compared to those with non-TR. The relationship between an early age of first contact (<20 years) and TR was significant in patients of Black ethnicity (OR 3.71, 95% CI 1.44–9.56); and patients of male gender (OR 3.13 95% CI 1.35–7.23).ConclusionsFor the majority of the TR group, antipsychotic TR is present from illness onset, necessitating increased consideration for the earlier use of clozapine.

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Geographical and temporal variations in clozapine prescription for schizophrenia

Cited by 75 publications

References 30 publications

Geographical Variation in Antipsychotic Drug Use in Elderly Patients with Dementia: A Nationwide Study

Geographical Variation in Antipsychotic Drug Use in Elderly Patients with Dementia: A Nationwide Study

Clozapine treatment and discontinuation in Iceland: A national longitudinal study using electronic patient records

Two distinct patterns of treatment resistance: clinical predictors of treatment resistance in first-episode schizophrenia spectrum psychoses

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