High-Risk Suicide Locations in Australia.

Importance: Although several interventions have been shown to be effective in preventing suicide at high-risk locations, the potential for these interventions to be deployed is limited by a lack of knowledge about where high-risk locations are and the factors associated with choosing these locations. Objective: To identify high-risk suicide locations in Australia and the factors associated with choosing these locations. Design, Setting, and Participants: This case-control study included data on individuals who died by suicide in Australia between January 2001 and December 2017, obtained from the National Coronial Information System. Data analysis was conducted from February to December 2021. Exposures: Sociodemographic, residential, incident time, and incident location variables. Main Outcomes and Measures: The scan statistic was used to detect spatial clusters of suicides in public locations. Suicide locations within significant clusters with at least 0.5 suicides per year were defined as high-risk locations. Multivariable logistic regression analyses were performed to examine the factors associated with choosing a high-risk location. Results: Over the study period, 10 701 suicides took place in public places. The individuals who died of suicide in public places included 8602 (80.4%) male individuals, and most were aged 25 to 49 years (5825 [54.5%]). A total of 17 high-risk suicide locations in Australia were detected. These involved 495 suicides, which accounted for 4.6% of suicides in public locations. For suicides at high-risk locations, 82.2% (407 of 495) occurred at cliffs and bridges. Being female (adjusted odds ratio [aOR], 1.73; 95% CI, 1.41-2.13), employed (aOR, 1.57; 95% CI, 1.20-2.04), never married (aOR, 1.64; 95% CI, 1.26-2.13), and from a major city (aOR, 3.94; 95% CI, 2.94-5.28) were associated with the choice of a high- over low-risk suicide location. High-risk locations tended to be in major cities. Conclusions and Relevance: This case-control study found 17 high-risk suicide locations in Australia and the factors associated with the choice of these locations. Actions should be taken to prevent suicide at these locations where possible.

Evaluating Population-Level Interventions and Exposures for Suicide Prevention.

Evaluations of interventions targeting the population level are an essential component of the policy development cycle. Pre-post designs are widespread in suicide prevention research but have several significant limitations. To inform future evaluations, our aim is to explore the three most frequently used approaches for assessing the association between population-level interventions or exposures and suicide - the pre-post design, the difference-in-difference design, and Poisson regression approaches. The pre-post design and the difference-in-difference design will only produce unbiased estimates of an association if there are no underlying time trends in the data and there is no additional confounding from other sources. Poisson regression approaches with covariates for time can control for underlying time trends as well as the effects of other confounding factors. Our recommendation is that the default position should be to model the effects of population-level interventions or exposures using regression methods that account for time effects. The other designs should be seen as fall-back positions when insufficient data are available to use methods that control for time effects.

Incidence of adverse mental health outcomes after sleeve gastrectomy compared with gastric bypass and restrictive bariatric procedures: a retrospective cohort study.

OBJECTIVE: This study examined rates of suicide and hospitalization with psychiatric diagnoses after sleeve gastrectomy compared with gastric bypass and restrictive procedures (gastric banding/gastroplasty). METHODS: This was a longitudinal retrospective cohort study comprising all patients who underwent primary bariatric surgery in New South Wales or Queensland, Australia, between July 2001 and December 2020. Hospital admission records, death registration, and cause of death records (if applicable) within these dates were extracted and linked. Primary outcome was death by suicide. Secondary outcomes were admissions with self-harm; substance-use disorder, schizophrenia, mood, anxiety, behavioral, and personality disorders; any of these; and psychiatric inpatient admission. RESULTS: A total of 121,203 patients were included, with median follow-up of 4.5 years per patient. There were 77 suicides, with no evidence of difference in rates by surgery type (rates [95% CI] per 100,000 person years: 9.6 [5.0-18.4] restrictive, 10.8 [8.4-13.9] sleeve gastrectomy, 20.4 [9.7-42.8] gastric bypass; p = 0.18). Rates of admission with self-harm declined after restrictive and sleeve procedures. Admission with anxiety disorders, any psychiatric diagnosis, and as a psychiatric inpatient increased after sleeve gastrectomy and gastric bypass, but not restrictive procedures. Admissions with substance-use disorder increased after all surgery types. CONCLUSIONS: Variable associations between bariatric surgeries and hospitalization with psychiatric diagnoses might indicate distinct vulnerabilities among patient cohorts or that differing anatomical and/or functional changes may contribute to effects on mental health.

Test cricketers score quickly during the 'nervous nineties': Evidence from a regression discontinuity design.

The 'nervous nineties' is a well-known cricket colloquialism that implies that batting within reach of 100 runs is mentally demanding. Despite common acceptance of this phenomenon, no study has used a historical test cricket dataset to examine how batting behaviour and performance changes on approach to a century. Accordingly, we explored opensource ball-by-ball data from 712 test cricket matches played between 2004 and 2022 to model the regression discontinuity of batting performance metrics either side of 100 runs. Models were fit using multi-level regression, adjusted for the clustering of balls within players (and where possible, the clustering of matches and innings within players). The analysis revealed that runs per ball and the probability of scoring a boundary increased as batters approached 100 runs. This was followed by a decline of -0.18 runs per ball (95% CI -0.22 to -0.14) and a three-percentage point decline (95% CI 2.2 to 3.8) in the probability of a boundary once a batter reached 100. The modelling revealed no evidence of a change in the probability of a dismissal before and after 100. Our results suggest many batters cope effectively with the psychological demands of playing through the nineties, including by batting aggressively and/or opportunistically to swiftly reach the milestone.

Preventing railway suicides through level crossing removal: a multiple-arm pre-post study design in Victoria, Australia.

PURPOSE: Rail level crossing removals to improve transport performance across metropolitan Melbourne (state of Victoria) resulted in new rail fencing and grade-separation of tracks from the surrounding environment at several sites. These design changes restricted pedestrian access to the rail tracks, which is a countermeasure known to prevent railway suicide in other settings. We examined whether any such suicide prevention effect followed the removals. METHODS: We used a multiple-arm pre-post design to test whether a decrease in monthly frequency of railway suicides occurred at level crossing removal sites (intervention sites), compared to randomly matched sites where level crossings had not yet been removed (control sites). We used data available in the Victorian Suicide Register covering the period 1st January 2008 to 30th June 2021. RESULTS: The mean monthly number of railway suicides decreased by 68% within a 500 m radius of intervention sites (RR: 0.32; CI 95% 0.11-0.74) and by 61% within a 1000 m radius of intervention sites (RR: 0.39; CI 95% 0.21-0.68). There was no evidence that the mean monthly number of railway suicides changed at the control sites, either within a 500 m radius (RR: 0.88; CI 95% 0.47-1.56) or a 1000 m radius (RR: 0.82; CI 95% 0.52-1.26). CONCLUSION: The reduction in railway suicides at locations where level crossings were removed, demonstrates the suicide prevention benefits that can be derived from a major infrastructure project even if not initially intended. Planning for major infrastructure projects should include consideration of these benefits, with designs incorporating features to maximise suicide prevention impact.

Lewis Acid-Catalyzed Halonium Generation for Morpholine Synthesis and Claisen Rearrangement.

We disclose here practical strategies toward the synthesis of morpholines and Claisen rearrangement products based on the divergent reactivity of a common halonium intermediate. These reactions employ widely available alkenes in a Lewis acid-catalyzed halo-etherification process that can then transform them into the desired products with exceptional regioselectivity for both activated and unactivated olefins. Our mechanistic probe reveals an interesting regiochemical kinetic resolution process.

Suicide and resilience-related Google searches during the first 12 months of the COVID-19 pandemic.

Online searches related to suicide may sometimes be an early proxy indicator for behavioural outcomes. We used interrupted time series regression analyses to examine changes in suicide and resilience-related Google searches worldwide and in the United States during the first 12 months of the COVID-19 pandemic. Searches for the word "suicide" were unchanged worldwide (-1%; 95%CI, -12%-11%) and in the US (-7%; 95%CI, -15%-2%) with decreased searches for "suicide methods" and increased searches for "how to kill yourself" and for resilience-related terms. This study provides potential evidence that suicides may not increase worldwide during the first year of the pandemic.

Halonium Catalysis: An Underutilized and Underexplored Catalytic Concept in Olefin Functionalizations.

Iodonium catalysis is described here to accomplish an intermolecular olefin oxyamination reaction. Urea is used as the O- and N-source to add across both activated and unactivated alkenes in a regioselective manner. Mechanistic studies confirm the presence of an iodonium intermediate.

Ct Dosimetry for The Australian Cohort Data Linkage Study.

Children undergoing computed tomography (CT) scans have an increased risk of cancer in subsequent years, but it is unclear how much of the excess risk is due to reverse causation bias or confounding, rather than to causal effects of ionising radiation. An examination of the relationship between excess cancer risk and organ dose can help to resolve these uncertainties. Accordingly, we have estimated doses to 33 different organs arising from over 900 000 CT scans between 1985 and 2005 in our previously described cohort of almost 12 million Australians aged 0-19 years. We used a multi-tiered approach, starting with Medicare billing details for government-funded scans. We reconstructed technical parameters from national surveys, clinical protocols, regulator databases and peer-reviewed literature to estimate almost 28 000 000 individual organ doses. Doses were age-dependent and tended to decrease over time due to technological improvements and optimisation.

The interactive evolution of human communication systems.

This paper compares two explanations of the process by which human communication systems evolve: iterated learning and social collaboration. It then reports an experiment testing the social collaboration account. Participants engaged in a graphical communication task either as a member of a community, where they interacted with seven different partners drawn from the same pool, or as a member of an isolated pair, where they interacted with the same partner across the same number of games. Participants' horizontal, pair-wise interactions led "bottom up" to the creation of an effective and efficient shared sign system in the community condition. Furthermore, the community-evolved sign systems were as effective and efficient as the local sign systems developed by isolated pairs. Finally, and as predicted by a social collaboration account, and not by an iterated learning account, interaction was critical to the creation of shared sign systems, with different isolated pairs establishing different local sign systems and different communities establishing different global sign systems.

The fitness and functionality of culturally evolved communication systems.

This paper assesses whether human communication systems undergo the same progressive adaptation seen in animal communication systems and concrete artefacts. Four experiments compared the fitness of ad hoc sign systems created under different conditions when participants play a graphical communication task. Experiment 1 demonstrated that when participants are organized into interacting communities, a series of signs evolve that enhance individual learning and promote efficient decoding. No such benefits are found for signs that result from the local interactions of isolated pairs of interlocutors. Experiments 2 and 3 showed that the decoding benefits associated with community evolved signs cannot be attributed to superior sign encoding or detection. Experiment 4 revealed that naive overseers were better able to identify the meaning of community evolved signs when compared with isolated pair developed signs. Hence, the decoding benefits for community evolved signs arise from their greater residual iconicity. We argue that community evolved sign systems undergo a process of communicative selection and adaptation that promotes optimized sign systems. This results from the interplay between sign diversity and a global alignment constraint; pairwise interaction introduces a range of competing signs and the need to globally align on a single sign-meaning mapping for each referent applies selection pressure.

Knowledge partitioning in categorization: boundary conditions.

Knowledge partitioning refers to the notion that knowledge can be held in independent and non-overlapping parcels. Partitioned knowledge may cause people to make contradictory decisions for identical problems in different circumstances. We report two experiments that explored the boundary conditions of knowledge partitioning in categorization. The studies examined whether or not people would partition their knowledge (1) when categorization rules were or were not verbalizable and (2) when the to-be-categorized stimuli comprised perceptually separable or integral dimensions. When learning difficulty was controlled, partitioning occurred across all combinations of verbalizability and integrality/separability, underscoring the generality of knowledge partitioning. Partitioning was absent only when the task was rapidly learned and people reached a high level of proficiency, suggesting that task difficulty plays a critical role in the emergence of partitioned knowledge.