Ethnic comparisons of antipsychotic use in schizophrenia

Clinical determinants, patterns and outcomes of antipsychotic medication prescribing in the treatment of schizophrenia and schizoaffective disorder: A naturalistic cohort study

BACKGROUND

Schizophrenia affects individuals, families, and systems, with treatment primarily being antipsychotic medications. Long-acting injectable (LAI) antipsychotics are increasingly being used. This study sought to identify predictors of antipsychotic choice, in terms of formulation (LAI vs oral) and class (FGA vs SGA), and clinical outcomes.

METHODS

123 patients who received LAI antipsychotics were diagnosis-matched to patients who received oral antipsychotics. Sociodemographic and clinical factors were extracted from the medical record, including indicators of illness severity. Groups were compared with Chi-Square and t-tests, and logistic regression models were used to identify independent predictors of antipsychotic choice.

RESULTS

Patients that received LAIs had longer admissions, more complex discharges, and greater illness severity; however, there were no differences in readmission rates. Independent predictors of LAIs included younger age, being single, and longer admission. Patients who received FGA LAIs were more likely to use substances and be undomiciled compared to SGA LAIs, with the only predictor being older age. Oral FGAs were more likely than Oral SGAs to be prescribed to older and female patients, as well as those with co-occurring substance use, complex discharges, and longer admissions.

CONCLUSIONS

Illness severity and duration of illness appear to drive choice of LAI vs. oral antipsychotic medication and FGA vs. SGA. While LAIs were prescribed to patients with greater illness severity, readmission rates were equivalent to those receiving oral medication, supporting the use of LAI in patients with greater illness severity. Rationales for prescribing LAIs to younger patients and FGAs to older patients are discussed.

Ethnic disparities in clozapine prescription for service-users with schizophrenia-spectrum disorders: a systematic review

Clozapine is the only licenced medication for treating treatment-resistant schizophrenia. Previous studies have suggested unequal rates of clozapine treatment by ethnicity among individuals with schizophrenia-spectrum disorders. One previous review has investigated this topic but was restricted to studies from the USA. This current review aims to synthesise the international literature regarding ethnic disparities in clozapine prescription amongst individuals with schizophrenia-spectrum disorders. We searched CINAHL, PubMed, Medline, Embase, APA PsycINFO and Open Grey and reviewed studies reporting on the proportion of service-users prescribed clozapine separately for different ethnic groups, in individuals with a primary diagnosis of schizophrenia or any schizophrenia-spectrum disorders. A narrative synthesis was conducted to integrate information from included studies. The review was registered in PROSPERO (Number: CRD42020221731). From 24 studies, there is strong, consistent evidence that Black and Hispanic service-users in the UK and the USA are significantly less likely to receive clozapine than White/Caucasian service-users after controlling for multiple demographic and clinical potential confounders. In New Zealand, Māori service-users were reported to be more likely to receive clozapine than those of White/European ethnicity. There is mixed evidence regarding Asian service-users in the UK. The mentioned disparities were observed in studies with TRS and non-TRS cohorts. The results imply that access to clozapine treatment varies among ethnic groups. These findings raise an ethical concern as they suggest a compromise of the standards of care in schizophrenia treatment practices. Interventions are needed to reduce clozapine prescribing disparities among ethnic communities.

Systematic review of racial disparities in clozapine prescribing

OBJECTIVE

To conduct a systematic review of published evidence on clozapine prescribing disparities across racial and ethnic categories, estimate the size of these disparities, and assess possible causes to inform future monitoring and intervention.

METHODS

Electronic databases (MEDLINE, Embase, PsycINFO, Web of Science) were searched for directly relevant studies. Three independent reviewers selected studies: (1) of US samples; (2) directly addressed ethnic and/or racial disparities in prescribing of antipsychotic medications; (3) identified specific ethnic and/or racial groups (e.g. White, Blacks, Hispanics, non-Hispanic etc.); (4) reported clozapine prescription rates and (5) reported relevant covariates (i.e. gender, age, co-morbidities etc.).

FINDINGS

16 studies met our eligibility criteria. All studies reported clozapine underutilization in ethnic and racial minority patients when compared to their white counterparts. These findings remained consistent despite different time periods, designs, data set types, and after controlling for relevant covariates such as: length of hospital stay, institutional setting, and disease severity.

CONCLUSION

The reasons for underutilization of clozapine in minority patients remain unclear. Various contributors can be categorized as: clinician-related factors (e.g. prescriber lack of experience), patient-related factors (e.g. distrust or suspicion of clinician), and institution-related factors (e.g. state operated facilities). Direct examination of these factors can help inform efforts to reduce clozapine prescription disparities.

Steady-State Clozapine and Norclozapine Pharmacokinetics in Maori and European Patients

Background

Clozapine is the most effective drug for treatment-resistant schizophrenia, but its use is limited by toxicity. Because ethnicity has been reported to affect clozapine metabolism, we compared its steady state pharmacokinetics in New Zealand Maori and European patients.

Methods

Clozapine and norclozapine steady state bioavailability was assessed over 24 h under fasting and fed conditions in 12 Maori and 16 European patients treated for chronic psychotic illnesses with stable once-daily clozapine doses. Plasma clozapine and norclozapine concentrations were assessed using liquid chromatography with tandem mass spectrometry; pharmacokinetic parameters were calculated using standard non-compartmental methods, and compared using unpaired t-tests.

Findings

Mean pharmacokinetic parameters (AUC, C_max and C_min) for clozapine and norclozapine were virtually identical in Maori and European subjects, under both fed and fasted conditions.

Discussion

Clozapine bioavailability does not vary between Maori and European patients, and thus does not need to be considered in prescribing decisions. Additional studies are needed to identify if there are differences between Maori and European populations for drugs metabolized by other enzyme pathways.

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Metabolism of clozapine, our most effective antipsychotic drug, was compared in New Zealand's two main ethnic groups.

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Clozapine pharmacokinetic parameters were similar in Maori and European patients.

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Accordingly, clozapine dosing does not need to take Maori or European ethnicity into account.

Clozapine is an essential medicine for treatment-resistant schizophrenia, but its use is limited by significant side-effects. We were interested to see if Maori and European patients in New Zealand differed in terms of clozapine pharmacokinetics, as this could influence both clinical response and side-effects. We found essentially no difference in clozapine pharmacokinetics between these groups, meaning that dosing decisions can be made based on clinical factors without regard to ethnicity.

Comparison of treatment patterns in schizophrenia between China and Japan (2001-2009)

INTRODUCTION

To date no study has compared the treatment patterns for schizophrenia specifically between China and Japan. This study examined the cross-national differences in the use of psychotropic drugs and electroconvulsive therapy (ECT) in schizophrenia.

METHOD

Data on 3248 schizophrenia inpatients (n = 1524 in China and n = 1724 in Japan) were collected by either chart review or interviews during the designated 3 study periods between 2001 and 2009. Patients' socio-demographic and clinical characteristics, prescriptions of psychotropic drugs, and ECT use were recorded using a standardized protocol and data collection procedure.

RESULTS

Multivariate analyses revealed that compared to their Japanese counterparts, Chinese inpatients had a shorter length of current hospitalization, were significantly less frequently prescribed second-generation antipsychotics (except clozapine), antipsychotic polypharmacy, benzodiazepines, and mood stabilizers, and more likely to receive clozapine, antidepressants, and ECT.

DISCUSSION

Substantial variations in inpatient treatment patterns for schizophrenia were found between China and Japan. The common use of ECT and clozapine in Chinese inpatients and the frequent use of antipsychotic polypharmacy and high antipsychotic doses in Japanese inpatients need to be addressed.

Antipsychotic prescribing for vulnerable populations: a clinical audit at an acute Australian mental health unit at two-time points

BACKGROUND

Antipsychotics are recognised as a critical intervention for schizophrenia and bipolar disorder. Guidelines globally endorse the routine practice of antipsychotic monotherapy, at the minimum effective dose. Even in treatment-resistant schizophrenia, clozapine use is endorsed before combining antipsychotics. This aim of this study was to review antipsychotic polytherapy alone, high-dose therapy alone, polytherapy and high-dose prescribing patterns in adults discharged from an inpatient mental health unit at two time-points, and the alignment of this prescribing with clinical guideline recommendations. Additionally, associations with polytherapy and high-dose antipsychotic prescribing, including patient and clinical characteristics, were explored.

METHODS

A retrospective clinical audit of 400 adults (200 patients at two different time-points) discharged with at least one antipsychotic. Preliminary findings and education sessions were provided to physicians between Cohorts. Outcomes (polytherapy alone, high-dose therapy alone, polytherapy and high-dose therapy) were compared between study Cohorts using chi-squared and rank-sum tests. Associations between outcomes and covariates were assessed using multivariable logistic regression.

RESULTS

Most patients (62.5%) were discharged on a single antipsychotic within the recommended dose range. There was a clear preference for prescribing second generation antipsychotics, and in this respect, prescribing is aligned with current evidence-based guidelines. However, sub-optimal prescribing practices were identified for both Cohorts in relation to polytherapy and high-dose antipsychotic rates. Involuntary treatment, frequent hospitalisations and previous clozapine use significantly increased the risk of all three prescribing outcomes at discharge.

CONCLUSIONS

In a significant minority, antipsychotic prescribing did not align with clinical guidelines despite increased training, indicating that the education program alone was ineffective at positively influencing antipsychotic prescribing practices. Further consideration should be given when prescribing antipsychotics for involuntary patients, people with frequent hospitalisations, and those who have previously trialled clozapine.

Antipsychotic prescribing and its correlates in New Zealand

OBJECTIVES

Antipsychotics are the cornerstone of schizophrenia management. There is substantial literature on their efficacy and optimal use. Doubts remain, however, regarding the translation of this knowledge into day-to-day practice. This study aimed to investigate antipsychotic prescribing in three New Zealand regions and its relationship to clinical guidelines and patient characteristics.

METHODS

We studied 451 patients discharged from inpatient units with a diagnosis of schizophrenia or a related disorder (International Classification of Disease, version 10) between July 2009 and December 2011. Available information included patient demography, legal status, prescribed medications, duration of index admission and prescriber's country of postgraduate training and years of postgraduate experience.

RESULTS

There was a high rate (33.7%) of multiple antipsychotic prescription, and lower than expected clozapine use (20%); Maori were prescribed clozapine more frequently than non-Maori (24% vs. 13%, respectively). Compulsory treatment was associated with more use of injectable medication and increased length of stay in hospital. Clinician characteristics did not significantly influence prescribing.

CONCLUSIONS

Observed prescribing practice aligned with existing guidelines except for antipsychotic polypharmacy and clozapine under-utilisation.

Cognitive neuropsychological functioning in New Zealand Māori diagnosed with schizophrenia

OBJECTIVE

Previous research suggests that New Zealand Māori may have an elevated rate of schizophrenia. However, there is limited evidence on important clinical features of the illness in this population. This study examined cognitive neuropsychological functioning in 54 adult Māori diagnosed with schizophrenia and 56 Māori controls. This study also examined associations between cognition, medication and symptoms of psychosis in the schizophrenia group.

METHOD

The groups were matched on socio-demographic variables, handedness and premorbid cognitive ability. Participants were assessed on neuropsychological tests of attention, executive ability, motor, premorbid ability, verbal/non-verbal memory and verbal fluency (English/Māori versions). The Positive and Negative Syndrome Scale was used to assess psychotic symptoms. Information on cultural identity, duration of illness, duration of untreated psychosis, medication and substance abuse was collected.

RESULTS

The performance of the schizophrenia group was significantly lower than the control group on all the neuropsychological tests, except the test of attention. The effect sizes were moderate to large: 0.78 for motor function; 1.3 for executive ability, verbal fluency and visual memory; 1.6 for verbal learning and 1.8 for verbal memory. These differences remained after adjustment for multiple comparisons and covariates. A higher dose of antipsychotic medication and a higher anticholinergic load were associated with greater verbal memory impairment (r = -0.38 and r = -0.38, respectively). A longer duration of illness was associated with greater impairment of verbal memory (rho = -0.48), verbal learning (rho = -0.41) and visual memory (rho = -0.44).

CONCLUSION

The findings for the schizophrenia group show a profile of generalised cognitive impairment with greater impairment of verbal memory. The cognitive impairment in this group was independent of psychotic symptoms, but was associated with a higher antipsychotic dose, higher anticholinergic load and longer duration of illness. These findings have implications for clinical prescribing practices and rehabilitation for New Zealand Māori diagnosed with schizophrenia.

Social and clinical descriptors of antipsychotic prescription

OBJECTIVE

To identify descriptors of Antipsychotic (AP) prescription, focusing on second generation antipsychotics (SGAs), polypharmacy, and long-acting injections (LAIs).

METHODS

Outpatients of the Bologna-Community-Mental-Health-Centres with at least one AP prescription were selected. Patients' characteristics, service utilization, and AP prescriptions were collected from administrative databases. Prescriptions were grouped by class (SGA vs. First Generation Antipsychotics), drug combination (polypharmacy vs. monotherapy), and preparation (LAIs vs. regular administration). Multi-variate analyses were performed to identify prescription descriptors among socio-demographic and clinical variables.

RESULTS

Among 6,074 patients and 41,121 AP prescriptions, SGAs were used in 70.7% of subjects, AP polypharmacy in 25.3%, and LAIs in 17.5%. SGAs were prescribed more often for young, Italian patients, with higher education, voluntary hospitalization, and high number of visits. Descriptors of AP polypharmacy were: high number of visits and hospitalization, length of treatment, non-urban residency, male gender, unemployment. Characteristics associated to LAI prescription were: long duration of treatment, high number of visits, compulsory admissions, non-Italian nationality, male gender, age > 34, low education, unmarried status.

CONCLUSIONS

Besides illness severity, this study identified different socio-demographic descriptors of AP choices, raising concerns on the equity of treatments. Efforts should be directed to investigate appropriateness of AP treatments especially in social disadvantaged populations.

Physical performance and disability in schizophrenia

Despite 50 years of pharmacological and psychosocial interventions, schizophrenia remains one of the leading causes of disability. Schizophrenia is also a life-shortening illness, caused mainly by poor physical health and its complications. The end result is a considerably reduced lifespan that is marred by reduced levels of independence, with few novel treatment options available.

Disability is a multidimensional construct that results from different, and often interacting, factors associated with specific types and levels of impairment. In schizophrenia, the most poignant and well characterized determinants of disability are symptoms, cognitive and related skills deficits, but there is limited understanding of other relevant factors that contribute to disability. Here we conceptualize how reduced physical performance interacts with aging, neurobiological, treatment-emergent, and cognitive and skills deficits to exacerbate ADL disability and worsen physical health. We argue that clearly defined physical performance components represent underappreciated variables that, as in mentally healthy people, offer accessible targets for exercise interventions to improve ADLs in schizophrenia, alone or in combination with improvements in cognition and health. And, finally, due to the accelerated aging pattern inherent in this disease – lifespans are reduced by 25 years on average – we present a training model based on proven training interventions successfully used in older persons. This model is designed to target the physical and psychological declines associated with decreased independence, coupled with the cardiovascular risk factors and components of the metabolic syndrome seen in schizophrenia due to their excess prevalence of obesity and low fitness levels.

Racial and ethnic disparities in the use of antipsychotic medication: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review and meta-analysis of published evidence on ethnic or racial disparities in the outpatient use versus non-use of antipsychotics and in the outpatient use of newer versus older antipsychotics.

METHOD

Electronic databases were searched for potentially relevant studies. Two independent reviewers conducted the review in three stages: title review, abstract review and full-text review. Included studies were those that: (a) report measures of disparity in the outpatient use of antipsychotic drugs in clearly defined racial or ethnic groups (b) have a primary focus on ethnic or racial disparities, and (c) have adjusted for factors known to influence medicine use. Odds ratios were pooled following the inverse-variance method of weighting effect sizes. I (2) statistics were calculated to quantify the amount of variation that is likely due to heterogeneity between studies. Funnel plots were produced and Egger's statistic was calculated to assess potential publication bias.

RESULTS

No significant differences were found in the odds of using any antipsychotics among African Americans (OR = 1.01, CI = 0.99-1.02) compared with non-African Americans and among Latinos (OR = 0.98, CI = 0.86-1.13) compared with non-Latinos. Small to moderate but statistically non-significant disparities were also noted in other ethnic groups: Asians (OR = 1.10, CI = 0.88-1.36), Maoris (OR = 0.78, CI = 0.53-1.13) and Pacific Islanders (OR = 0.97, CI = 0.84-1.11). Among those who received antipsychotic medication, African Americans (OR = 0.62, CI = 0.50-0.78) and Latinos (OR = 0.77, CI = 0.73-0.81) appeared to have lower odds of receiving newer antipsychotics compared with non-African Americans and non-Latinos.

CONCLUSION

No significant ethnic disparities in the use versus non-use of any antipsychotics were observed, but, among those who received antipsychotic treatment, ethnic minorities were consistently less likely than non-ethnic minorities to be treated with newer antipsychotics.

Clozapine use in schizophrenia: findings of the Research on Asia Psychotropic Prescription (REAP) studies from 2001 to 2009

OBJECTIVE

Optimizing treatment and outcomes for people with schizophrenia requires understanding of how evidence-based treatments are utilized. Clozapine is the most effective antipsychotic drug for treatment-refractory schizophrenia, but few studies have investigated trends and patterns of its use over time internationally. This study examined the prescription patterns of clozapine and its demographic and clinical correlates in Asia from 2001 to 2009.

METHOD

Clozapine prescriptions were collected in a sample of 6761 hospitalized schizophrenia patients in nine Asian countries and regions using a standardized protocol and data collection procedure.

RESULTS

Overall, the proportion of patients receiving clozapine prescriptions was stable across the three surveys from 2001 to 2009, ranging from 14.5% to 15.9%. However, the rates and patterns observed within different regions and countries at each survey differed considerably. Clozapine use decreased significantly over time in China, while it increased in Korea and Singapore. Multiple logistic regression analysis revealed that patients taking clozapine were significantly younger, had a higher dose of antipsychotic drugs in chlorpromazine equivalents, were more likely to be female, had fewer extrapyramidal symptoms, and had more negative symptoms, admissions and weight gain in the past month than those not receiving clozapine.

CONCLUSION

The variability in overall rates and changes in prescription rates over time in these samples suggest that factors other than psychopharmacological principles play an important role in determining the use of clozapine in schizophrenia in Asia.

Differences in patients' perceptions of Schizophrenia between Māori and New Zealand Europeans

OBJECTIVE

Māori (the Indigenous people of New Zealand) are disproportionately affected by mental illness and experience significantly poorer mental health compared to New Zealand Europeans. It is important to understand cultural differences in patients' ideas about mental illness in treatment settings. The aim of the present study was to investigate differences in illness perceptions between Māori and New Zealand Europeans diagnosed with schizophrenia.

METHOD

A total of 111 users of mental health services (68 Māori, 43 New Zealand European) in the greater Auckland and Northland areas who had been diagnosed with schizophrenia or other psychotic disorder were interviewed using the Brief Illness Perception Questionnaire and the Drug Attitude Inventory. District Health Board staff completed the Global Assessment of Functioning for each patient.

RESULTS

Māori with schizophrenia believed that their illness would continue significantly less time than New Zealand European patients did. Chance or spiritual factors were listed as causes of mental illness by only five Māori patients and no New Zealand European patients. Other illness perceptions, as well as attitudes towards medication, were comparable between groups. Across groups, the top perceived causes were drugs/alcohol, family relationships/abuse, and biological causes.

CONCLUSION

Illness perceptions provide a framework to assess patients' beliefs about their mental illness. Differences between Māori and New Zealand European patients' beliefs about their mental illness may be related to traditional Māori beliefs about mental illness. Knowledge of differences in illness perceptions provides an opportunity to design effective clinical interventions for both Māori and New Zealand Europeans.