Model-based testing for space-time interaction using point processes: An application to psychiatric hospital admissions in an urban area

Spatio-temporal interaction is inherent to cases of infectious diseases and occurrences of earthquakes, whereas the spread of other events, such as cancer or crime, is less evident. Statistical significance tests of space-time clustering usually assess the correlation between the spatial and temporal (transformed) distances of the events. Although appealing through simplicity, these classical tests do not adjust for the underlying population nor can they account for a distance decay of interaction. We propose to use the framework of an endemic-epidemic point process model to jointly estimate a background event rate explained by seasonal and areal characteristics, as well as a superposed epidemic component representing the hypothesis of interest. We illustrate this new model-based test for space-time interaction by analysing psychiatric inpatient admissions in Zurich, Switzerland (2007-2012). Several socio-economic factors were found to be associated with the admission rate, but there was no evidence of general clustering of the cases.Comment: 21 pages including 4 figures and 5 tables; methods are implemented in the R package surveillance (https://CRAN.R-project.org/package=surveillance

Online Survey of Medical and Psychological Professionals on Structured Instruments for the Assessment of Work Ability in Psychiatric Patients

Objective: To evaluate perceived needs and difficulties related to instruments for assessing work ability in individuals with mental disorders.Method: We conducted an online survey of 104 German-speaking medico-legal experts (forensic psychiatric and psychology experts, insurance physicians) and therapists.Results: The large majority of respondents reported they would welcome a standardized, structured instrument for the assessment of work ability. High predictiveness, inter-rater agreement, comprehensibility for laymen, and symptom validity were desired in roughly equal measure as the main characteristic of such an instrument. More women than men, and more medico-legal experts than therapists, considered symptom validation as always necessary. Pain, personality, and affective disorders were perceived to be the most difficult disorders in the context of work ability assessments.Conclusion: Our survey documents professionals' wish for a structured assessment of work ability in both medico-legal and therapeutic settings

Study protocol of an observational study in acute psychiatric home treatment: How does home treatment work? Identification of common factors and predictors of treatment success

Background: Systematic reviews indicated that home treatment is an effective and cost-saving alternative to conventional acute psychiatric treatment options. Treatment success has often been defined as a reduction of hospital admissions. In the current study, symptoms and well-being are assessed regularly during treatment as an indicator for treatment success. Patients' characteristics such as diagnosis, age, substance use, and motivation for treatment were discussed as predictors for treatment success. A second focal point of the study lies in the examination of the therapeutic relationship in terms of the outcome, which has not yet been systematically investigated in home treatment. Methods: This is an observational study with a prospective naturalistic design. Measurements are carried out at baseline, during and at the end of treatment as well as at the 3‑month follow-up. Patients' characteristics as potential predictors for treatment success will be assessed at baseline. In addition, the perceived relationship between the patients and the team will be measured daily and weekly throughout the treatment. Treatment success is by the changes in symptoms and general well-being assessed weekly. We aim to include 82 participants assigned to home treatment. Variance analyses with repeated measurements will be conducted to evaluate treatment success. Conclusion: By examining potential patient- and relationship-related predictors of treatment success, insights into relevant determining variables of treatment success in this setting are expected. The results might help to better identify who benefits the most from home treatment

Does psychopathology at admission predict the length of inpatient stay in psychiatry? Implications for financing psychiatric services

Background: The debate on appropriate financing systems in inpatient psychiatry is ongoing. In this context, it is important to control resource use in terms of length of stay (LOS), which is the most costly factor in inpatient care and the one that can be influenced most easily. Previous studies have shown that psychiatric diagnoses provide only limited justification for explaining variation in LOS, and it has been suggested that measures such as psychopathology might be more appropriate to predict resource use. Therefore, we investigated the relationship between LOS and psychopathological syndromes or symptoms at admission as well as other characteristics such as sociodemographic and clinical variables. Methods: We considered routine medical data of patients admitted to the Psychiatric University Hospital Zurich in the years 2008 and 2009. Complete data on psychopathology at hospital admission were available in 3,220 inpatient episodes. A subsample of 2,939 inpatient episodes was considered in final statistical models, including psychopathology as well as complete datasets of further measures (e.g. sociodemographic, clinical, treatment-related and psychosocial variables). We used multivariate linear as well as logistic regression analysis with forward selection procedure to determine the predictors of LOS. Results: All but two syndrome scores (mania, hostility) were positively related to the length of stay. Final statistical models showed that syndromes or symptoms explained about 5% of the variation in length of stay. The inclusion of syndromes or symptoms as well as basic treatment variables and other factors led to an explained variation of up to 25%. Conclusions: Psychopathological syndromes and symptoms at admission and further characteristics only explained a small proportion of the length of inpatient stay. Thus, according to our sample, psychopathology might not be suitable as a primary indicator for estimating LOS and contingent costs. This might be considered in the development of future costing systems in psychiatry

Modelling suicide and unemployment: a longitudinal analysis covering 63 countries, 2000-11

BACKGROUND: As with previous economic downturns, there has been debate about an association between the 2008 economic crisis, rising unemployment, and suicide. Unemployment directly affects individuals' health and, unsurprisingly, studies have proposed an association between unemployment and suicide. However, a statistical model examining the relationship between unemployment and suicide by considering specific time trends among age-sex-country subgroups over wider world regions is still lacking. We aimed to enhance knowledge of the specific effect of unemployment on suicide by analysing global public data classified according to world regions. METHODS: We retrospectively analysed public data for suicide, population, and economy from the WHO mortality database and the International Monetary Fund's world economic outlook database from 2000 to 2011. We selected 63 countries based on sample size and completeness of the respective data and extracted the information about four age groups and sex. To check stability of findings, we conducted an overall random coefficient model including all study countries and four additional models, each covering a different world region. FINDINGS: Despite differences in the four world regions, the overall model, adjusted for the unemployment rate, showed that the annual relative risk of suicide decreased by 1·1% (95% CI 0·8-1·4) per year between 2000 and 2011. The best and most stable final model indicated that a higher suicide rate preceded a rise in unemployment (lagged by 6 months) and that the effect was non-linear with higher effects for lower baseline unemployment rates. In all world regions, the relative risk of suicide associated with unemployment was elevated by about 20-30% during the study period. Overall, 41,148 (95% CI 39,552-42,744) suicides were associated with unemployment in 2007 and 46,131 (44,292-47,970) in 2009, indicating 4983 excess suicides since the economic crisis in 2008. INTERPRETATION: Suicides associated with unemployment totalled a nine-fold higher number of deaths than excess suicides attributed to the most recent economic crisis. Prevention strategies focused on the unemployed and on employment and its conditions are necessary not only in difficult times but also in times of stable economy. FUNDING: University of Zurich

Assessing a financial incentive for reducing length of stay of psychiatric inpatients: Implications for financing psychiatric services

QUESTIONS UNDER STUDY: Restricted government budgets are forcing countries to implement more efficient health measures. Unlike in somatic medicine, the process of evaluating payment systems in psychiatry in Switzerland is ongoing. A pilot approach in one psychiatric hospital, here called “new remuneration system (NRS)”, was introduced to better control length of stay (LOS) by combining a lump sum with degressive daily rates. This is a first evaluation of the NRS in terms of a reduction of the LOS, and the prevention of early readmissions by analysing meaningful outcome categories. METHODS: The total sample consisted of N = 66,626 psychiatric inpatient episodes and a subsample of N = 60,847. Data were collected from the hospital using the NRS and three comparison hospitals in the Canton of Zurich. The observation period covered 2005 to 2011, the years before and after the implementation of the NRS in 2009. To examine the outcome categories, general logistic models were used. RESULTS: The median LOS at all four hospitals was 21 days (IQR: 46–8). In the NRS-hospital, there was a significantly higher proportion of 6 to10-day stays after 2009, indicating an influence of the lumpsum measure. At the same time, data revealed a somewhat lower proportion of readmissions within 30 days in the NRS-hospital. In general, effect sizes were small. CONCLUSIONS: Within the observation period of three years since 2009, the NRS had a small influence on LOS and early readmissions. The stability of effects needs to be monitored. More sophisticated modellings of the NRS might lead to further insights.ISSN:1424-7860ISSN:1424-399

Relationship of suicide rates to economic variables in Europe: 2000-2011

Background It is unclear whether there is a direct link between economic crises and changes in suicide rates. Aims The Lopez-Ibor Foundation launched an initiative to study the possible impact of the economic crisis on European suicide rates. Method Data was gathered and analysed from 29 European countries and included the number of deaths by suicide in men and women, the unemployment rate, the gross domestic product (GDP) per capita, the annual economic growth rate and inflation. Results There was a strong correlation between suicide rates and all economic indices except GPD per capita in men but only a correlation with unemployment in women. However, the increase in suicide rates occurred several months before the economic crisis emerged. Conclusions Overall, this study confirms a general relationship between the economic environment and suicide rates; however, it does not support there being a clear causal relationship between the current economic crisis and an increase in the suicide rate

Age- and gender-specific mortality risk profiles for depressive outpatients with major chronic medical diseases

BACKGROUND: As leading causes of death, chronic medical diseases, particularly common cardiovascular diseases, are associated with depression. The combination of depression and chronic medical disease in turn is linked with poorer health and premature death. Despite numerous studies on mortality in people with depression and chronic medical disease, the effects of age and gender were not consistently considered. To appropriately estimate mortality in the clinical setting, we aimed to analyse age- and gender-specific mortality profiles in outpatients with depression and chronic medical disease by considering depression severity. METHODS: We examined data from N=327,018 outpatients with depression aged 18 years and older (mean=60 years), which we obtained from German electronic health-insurance claims data covering the years 2007-2010. We considered major chronic medical disease groups: cardiovascular diseases, diabetes, diseases of the respiratory system and cancer. To analyse both adjusted mortality risk and rates over one year in a comprehensive manner, we calculated General Estimation Equation (GEE) Poisson models for binary data. RESULTS: The mortality risk increased with age and was higher for males. Especially patients below 60 years of age with cancer or diabetes had an increased mortality risk, but not patients with cardiovascular disease. Mortality was comparably increased in patients with severe depression, diabetes or respiratory disease. LIMITATIONS: We did not have data from a control group without depression. CONCLUSIONS: Notably, not cardiovascular diseases but cancer and, to a lesser extent, diabetes, both in younger patients, respiratory diseases and severity of depression require particular attention in outpatient care to reduce mortality