Breast screening participation and degree of spread of invasive breast cancer at diagnosis in mental health service users: A population linkage study.

BACKGROUND: Women living with mental health conditions may not have shared in improvements in breast cancer screening and care. No studies have directly examined the link between reduced screening participation and breast cancer spread in women using mental health (MH) services. METHODS: Population-wide linkage of a population cancer register, BreastScreen register, and mental health service data set in women aged 50 to 74 years in New South Wales, Australia, from 2008 to 2017. Incident invasive breast cancers were identified. Predictors of degree of spread (local, regional, metastatic) at diagnosis were examined using partial proportional odds regression, adjusting for age, socioeconomic status, rurality, and patterns of screening participation. RESULTS: A total of 29 966 incident cancers were identified and included 686 (2.4%) in women with MH service before cancer diagnoses. More than half of MH service users had regional or metastatic spread at diagnosis (adjusted odds ratio, 1.63; 95% CI, 1.41-1.89). MH service users had lower screening participation; however, advanced cancer was more common even when adjusting for screening status (adjusted odds ratio, 1.53; 95% CI, 1.32-1.77). Advanced cancer was more common in women with severe or persistent MH conditions. CONCLUSIONS: Low screening participation rates explain only small part of the risk of more advanced breast cancer in women who use MH services. More study is needed to understand possible mechanisms contributing to more advanced breast cancer in women living with MH conditions. Health systems need strategies to ensure that women living with MH conditions enjoy population gains in breast cancer outcomes.

Vaccine-preventable hospitalisations in adult mental health service users: a population study.

BACKGROUND: Vaccine-preventable conditions cause preventable illness and may increase mortality in people living with mental illness. We examined how risks of hospitalisation for a wide range of vaccine-preventable conditions varied by age and sex among mental health (MH) service users. METHODS: Linked population data from New South Wales (NSW), Australia were used to identify vaccine-preventable hospitalisations (VPH) for 19 conditions from 2015 to 2020. Adult MH service users (n = 418 915) were compared to other NSW residents using incidence rates standardised for age, sex and socioeconomic status. Secondary analyses examined admissions for COVID-19 to September 2021. RESULTS: We identified 94 180 VPH of which 41% were influenza, 33% hepatitis B and 10% herpes zoster. MH service users had more VPH admissions [adjusted incidence rate ratio (aIRR) 3.2, 95% CI 3.1-3.3]. Relative risks were highest for hepatitis (aIRR 4.4, 95% CI 4.3-4.6), but elevated for all conditions including COVID-19 (aIRR 2.0, 95% CI 1.9-2.2). MH service users had a mean age of 9 years younger than other NSW residents at first VPH admission, with the largest age gap for vaccine-preventable pneumonias (11-13 years younger). The highest relative risk of VPH was among MH service users aged 45-65. CONCLUSIONS: MH service users have increased risk of hospitalisation for many vaccine-preventable conditions. This may be due to reduced vaccination rates, more severe illness requiring hospitalisation, greater exposure to infectious conditions or other factors. People living with mental illness should be prioritised in vaccination strategies.

Real-time analysis of hospital length of stay in a mixed SARS-CoV-2 Omicron and Delta epidemic in New South Wales, Australia.

BACKGROUND: The distribution of the duration that clinical cases of COVID-19 occupy hospital beds (the 'length of stay') is a key factor in determining how incident caseloads translate into health system burden. Robust estimation of length of stay in real-time requires the use of survival methods that can account for right-censoring induced by yet unobserved events in patient progression (e.g. discharge, death). In this study, we estimate in real-time the length of stay distributions of hospitalised COVID-19 cases in New South Wales, Australia, comparing estimates between a period where Delta was the dominant variant and a subsequent period where Omicron was dominant. METHODS: Using data on the hospital stays of 19,574 individuals who tested positive to COVID-19 prior to admission, we performed a competing-risk survival analysis of COVID-19 clinical progression. RESULTS: During the mixed Omicron-Delta epidemic, we found that the mean length of stay for individuals who were discharged directly from ward without an ICU stay was, for age groups 0-39, 40-69 and 70 +, respectively, 2.16 (95% CI: 2.12-2.21), 3.93 (95% CI: 3.78-4.07) and 7.61 days (95% CI: 7.31-8.01), compared to 3.60 (95% CI: 3.48-3.81), 5.78 (95% CI: 5.59-5.99) and 12.31 days (95% CI: 11.75-12.95) across the preceding Delta epidemic (1 July 2021-15 December 2021). We also considered data on the stays of individuals within the Hunter New England Local Health District, where it was reported that Omicron was the only circulating variant, and found mean ward-to-discharge length of stays of 2.05 (95% CI: 1.80-2.30), 2.92 (95% CI: 2.50-3.67) and 6.02 days (95% CI: 4.91-7.01) for the same age groups. CONCLUSIONS: Hospital length of stay was substantially reduced across all clinical pathways during a mixed Omicron-Delta epidemic compared to a prior Delta epidemic, contributing to a lessened health system burden despite a greatly increased infection burden. Our results demonstrate the utility of survival analysis in producing real-time estimates of hospital length of stay for assisting in situational assessment and planning of the COVID-19 response.

Substance use disorder screening and brief intervention in routine clinical practice in specialist adult mental health services: A systematic review.

BACKGROUND AND OBJECTIVES: Substance use disorders co-occurring with other mental health disorders are common and harmful. Clinical guidelines often recommend substance use screening and brief intervention though evidence about screening practice in mental health services is limited. This systematic review of routine clinical practice in adult mental health services aims to identify (a) proportions of screening and brief intervention, (b) how they are practised and (c) their outcomes. METHODS: We searched MEDLINE, PsycINFO and Embase and relevant Cochrane databases for articles until 31 July 2021 reporting on adults in English, regardless of geographical location. Backward snowball methods were used to locate additional articles. Screening, brief intervention and mental health services were defined. Data were extracted and variables compared related to setting, period, patient cohort, substances routine substance use disorder care pathways, and study quality was assessed. RESULTS: We identified 17 articles reporting routine screening within adult mental health services. Studies in community settings mainly reported on screening for alcohol and other substance use disorders, while studies from inpatient settings reported mainly on tobacco. There was marked variation in methods and screening proportions. Only two studies reported on brief intervention. CONCLUSION: This systematic review shows marked variation in mental health services routine screening practices with early focus on alcohol but more recently tobacco screening. We suggest approaches to enhancing implementation of screening and brief intervention in routine care, particularly using electronic health records.

Age-specific differences in cervical cancer screening rates in women using mental health services in New South Wales, Australia.

OBJECTIVE: Women living with mental health conditions have lower cervical cancer screening rates and higher mortality. More evidence is needed to target health system improvement efforts. We describe overall and age-specific cervical cancer screening rates in mental health service users in New South Wales. METHODS: Cervical cancer screening registers were linked to New South Wales hospital and community mental health service data. Two-year cervical screening rates were calculated for New South Wales mental health service users aged 20-69 years (n = 114,022) and other New South Wales women (n = 2,110,127). Rate ratios were compared for strata of age, socio-economic disadvantage and rural location, and overall rates compared after direct standardisation. RESULTS: Only 40.3% of mental health service users participated in screening, compared with 54.3% of other New South Wales women (incidence rate ratio = 0.74, 95% confidence interval = [0.74, 0.75]). Differences in age, social disadvantage or rural location did not explain screening gaps. Screening rates were highest in mental health service users aged <35 years (incidence rate ratios between 0.90 and 0.95), but only 15% of mental health service users aged >65 years participated in screening (incidence rate ratio = 0.27, 95% confidence interval = [0.24, 0.29]). CONCLUSION: Women who use mental health services are less likely to participate in cervical cancer screening. Rates diverged from population rates in service users aged ⩾35 years and were very low for women aged >65 years. Intervention is needed to bridge these gaps. New screening approaches such as self-testing may assist.

Mental health service utilisation and reoffending in offenders with a diagnosis of psychosis receiving non-custodial sentences: A 14-year follow-up study.

OBJECTIVE: While psychosis is considered a risk factor for offending, little is reported about mental health service utilisation in offenders with psychosis and its relationship with reoffending. We examined the association between contact with mental health services and reoffending in those diagnosed with psychosis. METHODS: We linked health and offending records in New South Wales (Australia) and identified all individuals with a diagnosis of psychosis and a subsequent offence resulting in a non-custodial sentence between 2001 and 2012. We examined the incidence and risk factors for reoffending, and time to reoffending between 2001 and 2015 using Cox regression and Kaplan-Meier survival methods. We specifically examined the association between clinical contact with community mental health services following the index offence and reoffending. RESULTS: Of the 7393 offenders with psychosis, 70% had clinical contact and 49% reoffended. There was a linear relationship between an increased number of clinical contacts and reduced risk of reoffending: those with no clinical contact had more than a fivefold risk of reoffending compared to those with the highest number of contacts (adjusted hazard ratio = 5.78, 95% confidence interval = [5.04, 6.62]). Offenders with substance-related psychosis and those convicted of non-violent offences had fewer clinical contacts and higher rates of reoffending when compared with controls (adjusted hazard ratio = 1.29, 95% confidence interval = [1.13, 1.47] and adjusted hazard ratio = 1.26, 95% confidence interval = [1.18, 1.35], respectively). CONCLUSION: This study supports an association between more frequent mental health service use and reduced risk of reoffending. Efforts to enhance mental health service utilisation in those with psychosis who are at a higher risk of reoffending should be promoted.

Growth in emergency department self-harm or suicidal ideation presentations in young people: Comparing trends before and since the COVID-19 first wave in New South Wales, Australia.

INTRODUCTION: Self-harm presentations in children and young people have increased internationally over the last decade. The COVID-19 pandemic has the potential to worsen these trends. OBJECTIVE: To describe trends in emergency department self-harm or suicidal ideation presentations for children and young people in New South Wales before and since the COVID-19 pandemic. METHODS: We studied presentations for self-harm or suicidal ideation by 10- to 24-year-olds to New South Wales emergency departments, using interrupted time series analysis to compare annualised growth before COVID (2015 to February 2020) and since COVID (March 2020 to June 2021). Subgroup analyses compared age group, gender, triage category, rurality and disadvantage. Time series decomposition via generalised additive models identified long-term, seasonal and short-term trends. RESULTS: Self-harm or suicidal ideation presentations by young people in New South Wales increased by 8.4% per annum pre-COVID. Growth accelerated since COVID, to 19.2% per annum, primarily due to increased presentations by females aged 13-17 years (47.1% per annum since COVID, from 290 per 10,000 in 2019 to 466 per 10,000 in 2021). Presentations in males aged 10-24 years did not increase since COVID (105.4 per 10,000 in 2019, 109.8 per 10,000 in 2021) despite growing 9.9% per annum before COVID. Presentation rates accelerated significantly in socio-economically advantaged areas. Presentations in children and adolescents were strongly linked to school semesters. CONCLUSION: Emergency department self-harm or suicidal ideation presentations by New South Wales young people grew steadily before COVID. Understanding the sustained increase remains a priority. Growth has increased since COVID particularly for adolescent females, but not among adolescent males. Surprisingly, the largest post-COVID increases in annual growth occurred in socio-economically advantaged and urban regions. The COVID-19 pandemic appears to have added new challenges, particularly in females in the developmentally critical early adolescent and teenage years.

Breast cancer screening participation in women using mental health services in NSW, Australia: a population study.

PURPOSE: Population screening programs have contributed to reduced breast cancer mortality, but disadvantaged or vulnerable groups may not have shared these improvements. In North American and European studies, women living with mental health conditions have reduced breast screening rates. There are no current Australasian data to support health system planning and improvement strategies. METHODS: The New South Wales (NSW) BreastScreen program offers free screening to NSW women aged 50-74. We compared 2-year breast screening rates for mental health service users (n = 33,951) and other NSW women (n = 1,051,495) in this target age range, after standardisation for age, socioeconomic status and region of residence. Mental health service contacts were identified through linkage to hospital and community mental health data. RESULTS: Only 30.3% of mental health service users participated in breast screening, compared with 52.7% of other NSW women (crude incidence rate ratio 0.57, 95% CI 0.56-0.59). Standardisation for age, socioeconomic disadvantage or rural residence did not alter this screening gap. Around 7000 fewer women received screening than would be expected from comparable population rates. Screening gaps were largest in women over 60 and in socioeconomically advantaged areas. Women with severe or persistent mental illness had slightly higher screening rates than other mental health service users. CONCLUSIONS: Low breast cancer screening participation rates for NSW mental health service users suggest significant risk of later detection, possibly leading to more extensive treatment and premature mortality. Focussed strategies are needed to support greater breast screening participation for NSW women who use mental health services.

Amphetamine use and psychiatric admissions: a 10-year perspective.

OBJECTIVE: We aimed to (i) describe the 10-year trend in admissions associated with amphetamine use, (ii) describe the distinguishing characteristics of people with an amphetamine-related diagnosis (ARD) and (iii) examine predictors of repeated admissions among people with an ARD. METHOD: We conducted a retrospective cohort study. We (i) counted the number of admissions with an ARD and evaluated any trends, and using univariate and multivariate tests, (ii) compared those who had an ARD with those who did not and (iii) compared those with an ARD who had one, two to four, and five or more admissions. RESULTS: Admissions associated with amphetamine use increased between 2009 and 2015. Those with an ARD had significant differences in demographics, diagnosis and pattern of service use relative to those without an ARD. Amongst those with an ARD, a higher number of admissions was positively associated with a schizophrenia diagnosis but inversely associated with a transient psychotic disorder diagnosis. CONCLUSIONS: The increase in admissions associated with amphetamine use indicates that people with an ARD posed major demands on inpatient services. Targeting amphetamine treatment to those with psychotic disorders, both schizophrenia and transient psychotic disorders, may reduce hospital-related costs and re-admissions.

Disengagement from mental health treatment and re-offending in those with psychosis: a multi-state model of linked data.

BACKGROUND AND AIMS: Individuals with psychosis are over-represented in the criminal justice system and, as a group, are at elevated risk of re-offending. Recent studies have observed an association between increased contacts with mental health services and reduced re-offending, as well as reduced risk of re-offending in those who are ordered to mental health treatment rather than punitive sanctions. In furthering this work, this study examines the effect of disengagement from mental health treatment on probability of re-offence in offenders with psychosis over time. METHODS: Data linkage was conducted with judicial, health and mortality datasets from New South Wales, Australia (2001-2015). The study population included 4960 offenders with psychosis who received non-custodial sentences and engaged with community-based mental health treatment. Risk factors for leaving treatment and/or reconviction were examined using multivariate cox regression. Further, a multi-state model was used to observe the probabilities associated with individuals moving between three states: conviction, disengagement from mental health treatment and subsequent re-conviction. RESULTS: A threefold increase was observed in the risk of re-offending for those who disengaged from treatment compared to those who did not (aHR = 2.76, 95% CI 1.65-4.62, p < 0.001). The median time until re-offence was 195 days, with the majority (67%) being convicted within one year of leaving treatment. A higher risk of leaving treatment was found for those born outside of Australia, with substance-related psychosis, and a history of violent offence. CONCLUSIONS: The findings argue for an emphasis on continued engagement with mental health services following release for offenders with psychosis and identify subgroups within this population for whom concentrated efforts regarding treatment retention should be targeted.

Identifying patients using antidepressants for the treatment of depression: A predictive algorithm for use in pharmaceutical and medical claims data.

PURPOSE: Records of antidepressant dispensings are often used as a surrogate measure of depression. However, as antidepressants are frequently prescribed for indications other than depression, this is likely to result in misclassification. This study aimed to develop a predictive algorithm that identifies patients using antidepressants for the treatment of depression. METHODS: Pharmaceutical Benefits Scheme (PBS) and Medicare Benefits Schedule (MBS) claims data were linked to follow-up questionnaires (completed in 2012-2013) for participants of the 45 and Up Study-a cohort study of residents of New South Wales, Australia, aged 45 years and older. The sample composed participants who were dispensed an antidepressant in the 30 days prior to questionnaire completion (n = 3162). An algorithm based on patient characteristics, pharmaceutical dispensings, and claims for mental health services was built using group-lasso interaction network (glinternet), with self-reported receipt of treatment for depression as the outcome. The predictive performance of the algorithm was assessed via bootstrap resampling. RESULTS: The algorithm composes 15 main effects and 11 interactions, with type of antidepressant dispensed and claims for mental health services the strongest predictors. The ability of the algorithm to discriminate between antidepressant users with and without depression was 0.73. At a predicted probability cut-off of 0.6, specificity was 93.8% and sensitivity was 23.6%. CONCLUSIONS: Using this algorithm with a high probability cut-off yields high specificity and facilitates the exclusion of individuals using antidepressants for indications other than depression, thereby mitigating the risk of confounding by indication when evaluating the outcomes of antidepressant use.

Community treatment orders increase community care and delay readmission while in force: Results from a large population-based study.

OBJECTIVE: There is debate about the effectiveness of community treatment orders in the management of people with a severe mental illness. While some case-control studies suggest community treatment orders reduce hospital readmissions, three randomised controlled trials find no effects. These randomised controlled trials measure outcomes over a longer period than the community treatment order duration and assess the combined effectiveness of community treatment orders both during and after the intervention. This study examines the effectiveness of community treatment orders in a large population-based sample, restricting observation to the period under a community treatment order. METHODS: All persons ( n = 5548) receiving a community treatment order in New South Wales, Australia, over the period 2004-2009 were identified. Controls were matched using a propensity score based on demographic, clinical and prior care variables. A baseline period equal to each case's duration of treatment was constructed. Treatment effects were compared using zero-inflated negative binomial regression, adjusting for demographics, clinical characteristics and pre-community treatment order care. RESULTS: Compared to matched controls, people on community treatment orders were less likely to be readmitted (odds ratio = 0.90, 95% confidence interval = [0.84, 0.97]) and had a significantly longer time to their first readmission (incidence rate ratio = 1.47, 95% confidence interval = [1.36, 1.58]), fewer hospital admissions (incidence rate ratio = 0.90, 95% confidence interval = [0.84, 0.96]) and more days of community care (incidence rate ratio = 1.55, 95% confidence interval = [1.51, 1.59]). Increased community care and delayed first admission were found for all durations of community treatment order care. Reduced odds of readmission were limited to people with 6 months or less of community treatment order care, and reduced number of admissions and days in hospital to people with prolonged (>24 months) community treatment order care. CONCLUSION: In this large population-based study, community treatment orders increase community care and delay rehospitalisation while they are in operation. Some negative findings in this field may reflect the use of observation periods longer than the period of active intervention.

Amphetamine availability predicts amphetamine-related mental health admissions: A time series analysis.

OBJECTIVE: Amphetamine use and availability have increased in Australia and there are concerns that this has led to more frequent hospital admissions with amphetamine-related psychosis. This study examines whether amphetamine-related admissions to mental health units are more common at times of greater amphetamine availability. METHODS: We conducted an ecological study using aggregate crime and health service data for NSW, Australia, from January 2000 to March 2015. Amphetamine-related criminal incidents (arrests or cautions for possession or use) were used as an indirect measure of amphetamine availability. Semiparametric time series analysis was used to compare monthly arrest rates to monthly hospitalisation rates for (1) amphetamine abuse or dependence, (2) amphetamine-related psychosis and (3) any psychosis. RESULTS: Amphetamine-related admissions to NSW mental health units have increased four- to fivefold since 2009 and comprised approximately 10% of all admissions to these units in early 2015. There was a significant association between arrests and amphetamine-related admissions. After adjustment for seasonal variation, this effect demonstrated a time lag of 1-2 months. There was no relationship between amphetamine arrests and overall admissions for psychosis. CONCLUSION: Greater amphetamine availability significantly predicts admissions for amphetamine use disorders and amphetamine-related psychosis. Better treatment strategies are needed to break the nexus between drug availability and drug-related harm.

Six years of national mental health seclusion data: the Australian experience.

OBJECTIVES: Reducing or eliminating seclusion from mental health care settings has been a national priority for Australia since 2005. This paper describes Australia's national seclusion data collection, and summarises changes in seclusion rates in Australian public mental health services. METHODS: Seclusion events per 1000 patient days were calculated from 2009-2010 to 2014-2015 utilising state and territory administrative data sources. Combined national data were used to calculate results for a number of service characteristics, such as target population and location of the service. RESULTS: The rate of seclusion events decreased by 43% over the 6 years. Child and adolescent services reported consistently higher rates of seclusion, but a shorter duration of seclusion episodes, compared with other service types. There is high variation in seclusion rates between individual services (range 0.0-53.0 seclusion events per 1000 bed days in 2014-2015). CONCLUSIONS: Seclusion event rates in Australia's specialised public acute mental health hospital services are declining. The use of existing administrative data was instrumental in establishing a national data source to facilitate the monitoring and reporting of progress of seclusion reduction strategies.

Trends in diagnosis of bipolar disorder: Have the boundaries changed?

OBJECTIVE: There are concerns that the diagnostic boundaries of bipolar disorder have expanded. This study seeks evidence of change in diagnostic practice at three boundaries: the 'lower' boundary with subclinical mood conditions, the 'lateral' boundary with other mental health conditions (psychotic, anxiety, substance and personality disorders) and the 'internal' boundary within affective disorders. METHODS: Diagnoses recorded in health system administrative data collections were used as a measure of clinician diagnostic behaviour. We examined all diagnoses made by public (state operated) inpatient and community mental health services in New South Wales, Australia, from 2003 to 2014. RESULTS: A total of 31,746 people had at least one recorded diagnosis of bipolar disorder in the period. There was a significant upward trend in the age-standardised population rate of diagnosis of bipolar disorder. Bipolar disorders made up an increasing proportion of psychosis diagnoses. There was no increase in the rate of comorbid diagnosis of bipolar disorders with non-psychotic disorders or in the likelihood of diagnosis of bipolar disorder at first or subsequent episodes of depression. There were significant reductions in diagnoses of schizophrenia, particularly in younger people. CONCLUSION: There may be some increase in diagnoses of bipolar disorder in New South Wales public mental health services. However, some changes in diagnosis, particularly in younger adults, may reflect movement away from diagnoses of schizophrenia towards a range of other diagnoses, rather than specific movement towards bipolar disorder. Expansion of bipolar disorder may have been more marked in private practice settings and may have involved the poorly defined bipolar II subtype.

Stimulant use disorders in people with psychosis: a meta-analysis of rate and factors affecting variation.

OBJECTIVE: Stimulant abuse and dependence often complicate the care of people with psychotic disorders. This study systematically reviews the prevalence estimates reported for stimulant abuse and dependence in people with psychotic disorders, and examines personal, clinical, regional and methodological factors which explain variation in these rates. METHODS: PsychINFO, EMBASE and MEDLINE (1946-2013) were searched systematically for studies reporting on stimulant drug use disorders in representative samples of people with psychotic disorders. Random effects models estimated the pooled rate of a stimulant use disorder, defined to include stimulant abuse and stimulant dependence. Study characteristics associated with heterogeneity in rates of stimulant use disorder were examined by subgroup analyses for categorical variables, by meta-regression for continuous independent variables and by multiple meta-regression. RESULTS: Sixty-four studies provided 68 estimates of lifetime or recent stimulant use disorders in 22,500 people with psychosis. The pooled rate of stimulant use disorder was 8.9% (95% CI 7.4%, 10.5%). Higher rates of stimulant use disorders were reported in studies of affective psychosis, studies from inpatient settings, studies from the USA and Australia, and studies with higher rates of cannabis disorder; in multiple meta-regression analysis these factors explained 68% of between-study variance. Rates of stimulant use disorder were stable over time, and unrelated to age, sex, stage of psychosis, type of stimulant drug or study methodology factors. CONCLUSIONS: Reported rates of stimulant use disorder in people with psychosis are much higher than in the general population but vary widely and are associated with regional, service setting and clinical differences between studies. It is likely that stimulants contribute to the overall burden of psychosis, and that social and environmental factors combine with drug and illness-related factors to influence stimulant use in psychosis.

Cannabis and stimulant disorders and readmission 2 years after first-episode psychosis.

BACKGROUND: Few studies have examined the impact of stimulant use on outcome in early psychosis. Ceasing substance use may lead to positive outcomes in psychosis. AIMS: To examine whether baseline cannabis or stimulant disorders and ongoing drug use predict readmission within 2 years of a first psychosis admission. METHOD: Predictors of readmission were examined with Cox regression in 7269 people aged 15-29 years with a first psychosis admission. RESULTS: Baseline cannabis and stimulant disorders did not predict readmission. A stimulant disorder diagnosis prior to index psychosis admission predicted readmission, but a prior cannabis disorder diagnosis did not. Ongoing problem drug use predicted readmission. The lowest rate of readmission occurred in people whose baseline drug problems were discontinued. CONCLUSIONS: Prior admissions with stimulant disorder may be a negative prognostic sign in first-episode psychosis. Drug use diagnoses at baseline may be a good prognostic sign if they are identified and controlled.

Stimulant and other substance use disorders in schizophrenia: prevalence, correlates and impacts in a population sample.

OBJECTIVES: Stimulants may worsen psychotic symptoms but there is limited evidence about the impact of stimulant abuse in people with schizophrenia. This study examined the prevalence and correlates of stimulant and other drug disorders in a population-based sample of people with schizophrenia, examining associations with frequent service use, physical health comorbidities and accommodation instability. METHODS: New South Wales (NSW) hospital, community mental health and emergency department data were used to examine health service contact over 5 years in 13,624 people with a diagnosis of schizophrenia. Associations of stimulant disorders were examined with multinomial logistic regression, comparing people with no substance disorders to those with cannabis disorders, stimulant disorders or both. RESULTS: Of people with schizophrenia, 51% had substance disorders, including 14% with stimulant disorders. Stimulant disorders were more common in young adults and in urban areas, less common in migrants, and unrelated to initial social disadvantage. More than 80% of those with stimulant disorders also had cannabis disorders. Service use and harms were most common in this group, including frequent mental health admissions (59%), frequent emergency department presentations (52%), admissions with injury or self-harm (44%), infectious disease diagnoses (22%), multiple changes of residence (61%), movement to more disadvantaged locations (42%) and periods of homelessness (18%). People with stimulant disorders alone had higher rates of self-harm, infectious disease and non-mental health admissions than people with cannabis disorders alone. CONCLUSIONS: Stimulant disorders occur in people with schizophrenia and in first-episode psychosis at rates more than 10 times that of the broader population. Stimulant disorders are likely to worsen the burden of psychosis, and strategies are needed to engage and support the highly disadvantaged group of people with schizophrenia who have cannabis and stimulant disorders.

Comparing algorithms for deriving psychosis diagnoses from longitudinal administrative clinical records.

PURPOSE: Registers derived from administrative datasets are valuable tools in psychosis research, but diagnostic accuracy can be problematic. We sought to compare the relative performance of four methods for assigning a single diagnosis from longitudinal administrative clinical records when compared with reference diagnoses. METHODS: Diagnoses recorded in inpatient and community mental health records were compared to research diagnoses of psychotic disorders obtained from semi-structured clinical interviews for 289 persons. Diagnoses were derived from administrative datasets using four algorithms; 'At least one' diagnosis, 'Last' or most recent diagnosis, 'Modal' or most frequently occurring diagnosis, and 'Hierarchy' in which a diagnostic hierarchy was applied. Agreements between algorithm-based and reference diagnoses for overall presence/absence of psychosis and for specific diagnoses of schizophrenia, schizoaffective disorder, and affective psychosis were examined using estimated prevalence rates, overall agreement, ROC analysis, and kappa statistics. RESULTS: For the presence/absence of psychosis, the most sensitive and least specific algorithm ('At least one' diagnosis) performed best. For schizophrenia, 'Modal' and 'Last' diagnoses had greatest agreement with reference diagnosis. For affective psychosis, 'Hierarchy' diagnosis performed best. Agreement between clinical and reference diagnoses was no better than chance for diagnoses of schizoaffective disorder. Overall agreement between administrative and reference diagnoses was modest, but may have been limited by the use of participants who had been screened for likely psychosis prior to assessment. CONCLUSION: The choice of algorithm for extracting a psychosis diagnosis from administrative datasets may have a substantial impact on the accuracy of the diagnoses derived. An 'Any diagnosis' algorithm provides a sensitive measure for the presence of any psychosis, while 'Last diagnosis' is more accurate for specific diagnosis of schizophrenia and a hierarchical diagnosis is more accurate for affective psychosis.

Accuracy of automatic syndromic classification of coded emergency department diagnoses in identifying mental health-related presentations for public health surveillance.

BACKGROUND: Syndromic surveillance in emergency departments (EDs) may be used to deliver early warnings of increases in disease activity, to provide situational awareness during events of public health significance, to supplement other information on trends in acute disease and injury, and to support the development and monitoring of prevention or response strategies. Changes in mental health related ED presentations may be relevant to these goals, provided they can be identified accurately and efficiently. This study aimed to measure the accuracy of using diagnostic codes in electronic ED presentation records to identify mental health-related visits. METHODS: We selected a random sample of 500 records from a total of 1,815,588 ED electronic presentation records from 59 NSW public hospitals during 2010. ED diagnoses were recorded using any of ICD-9, ICD-10 or SNOMED CT classifications. Three clinicians, blinded to the automatically generated syndromic grouping and each other's classification, reviewed the triage notes and classified each of the 500 visits as mental health-related or not. A "mental health problem presentation" for the purposes of this study was defined as any ED presentation where either a mental disorder or a mental health problem was the reason for the ED visit. The combined clinicians' assessment of the records was used as reference standard to measure the sensitivity, specificity, and positive and negative predictive values of the automatic classification of coded emergency department diagnoses. Agreement between the reference standard and the automated coded classification was estimated using the Kappa statistic. RESULTS: Agreement between clinician's classification and automated coded classification was substantial (Kappa = 0.73. 95% CI: 0.58 - 0.87). The automatic syndromic grouping of coded ED diagnoses for mental health-related visits was found to be moderately sensitive (68% 95% CI: 46%-84%) and highly specific at 99% (95% CI: 98%-99.7%) when compared with the reference standard in identifying mental health related ED visits. Positive predictive value was 81% (95% CI: 0.57 - 0.94) and negative predictive value was 98% (95% CI: 0.97-0.99). CONCLUSIONS: Mental health presentations identified using diagnoses coded with various classifications in electronic ED presentation records offers sufficient accuracy for application in near real-time syndromic surveillance.