Metropolitan Perth Research Articles

Prevalence of Macropod Progressive Periodontal Disease (“lumpy jaw”) in wild western grey kangaroos (Macropus fuliginosus)

Macropod Progressive Periodontal Disease (MPPD), colloquially referred to as “lumpy jaw”, is a commonly observed disease in captive macropods. However, the prevalence of this disease in the wild is largely unknown. A systematic study of MPPD in wild macropods would provide an indication of the endemic presence of this disease in wild populations, and could assist those managing disease in captive populations, by highlighting potential risk factors for disease development. Utilising kangaroos culled as part of a population management program, this study used visual observation and computer tomography (CT) of skulls to investigate the prevalence of MPPD in wild western grey kangaroos (Macropus fuliginosus) from the Perth metropolitan region, Western Australia. The sample suitable for visual and CT analysis comprised 121 specimens, 71 (58.7%) male and 50 (41.3%) female, with the mean age for all 121 specimens being 4.5 years (±2.63 SD). No evidence of MPPD was detected in any of the specimens examined. Overabundance may not be associated with the development of MPPD, as previously considered, and age-related factors should not be eliminated. This results may reflect low susceptibility to MPPD in western grey kangaroos, given low prevalence is reported in this species in captive populations. Further investigation into species-specificity is recommended, and should include samples with soft tissue to improve sensitivity of disease detection. Surveillance of MPPD in wild populations of macropods helps to improve our understanding of the biological significance, development and potential spread of this disease. Notably, this information may assist in the management of MPPD in captive populations, and may have a positive impact on both the welfare and conservation of macropods in captivity.

Variation in reproductive effort, genetic diversity and mating systems across Posidonia australis seagrass meadows in Western Australia.

Populations at the edges of their geographical range tend to have lower genetic diversity, smaller effective population sizes and limited connectivity relative to centre of range populations. Range edge populations are also likely to be better adapted to more extreme conditions for future survival and resilience in warming environments. However, they may also be most at risk of extinction from changing climate. We compare reproductive and genetic data of the temperate seagrass, Posidonia australis on the west coast of Australia. Measures of reproductive effort (flowering and fruit production and seed to ovule ratios) and estimates of genetic diversity and mating patterns (nuclear microsatellite DNA loci) were used to assess sexual reproduction in northern range edge (low latitude, elevated salinities, Shark Bay World Heritage Site) and centre of range (mid-latitude, oceanic salinity, Perth metropolitan waters) meadows in Western Australia. Flower and fruit production were highly variable among meadows and there was no significant relationship between seed to ovule ratio and clonal diversity. However, Shark Bay meadows were two orders of magnitude less fecund than those in Perth metropolitan waters. Shark Bay meadows were characterized by significantly lower levels of genetic diversity and a mixed mating system relative to meadows in Perth metropolitan waters, which had high genetic diversity and a completely outcrossed mating system. The combination of reproductive and genetic data showed overall lower sexual productivity in Shark Bay meadows relative to Perth metropolitan waters. The mixed mating system is likely driven by a combination of local environmental conditions and pollen limitation. These results indicate that seagrass restoration in Shark Bay may benefit from sourcing plant material from multiple reproductive meadows to increase outcrossed pollen availability and seed production for natural recruitment.

Reducing car idling at primary schools: An intervention study of parent behaviour change in Perth, Western Australia.

There is increasing evidence that exposure to traffic-related air pollution is related to childhood respiratory symptoms. This study demonstrated the effectiveness of an anti-idling behavioural intervention targeting parents at primary schools. Based on two focus group discussions with parents, a low-intensity 4-week anti-idling intervention was developed, comprising onsite signage, four newsletters, and two fact sheets. Exposure to selected air pollutants was assessed during pick-up and drop-off times pre- and postintervention at 12 randomly selected independent schools (10 intervention and 2 control) across the Perth metropolitan area. The study results showed that a low-intensity behavioural intervention can be an effective strategy to affect parents' attitude towards vehicle idling. This was demonstrated by the reduced number of idling vehicles observed in 8 of the 10 intervention schools and decreased overall particulate matter concentration after the anti-idling intervention. Anti-idling education can be effective in promoting clean travel behaviours and has potential health benefits for school children. SO WHAT?: This intervention study provides insights on the significant effect of anti-idling education on parents' behaviour towards air quality and children's health. These promising findings warrant further rigorous actions on anti-idling education and enforcement.

To be seen and heard: Enhancing student engagement to support university aspirations and expectations for students from low socioeconomic status backgrounds

An important goal for educators is to foster student engagement in order to support a sense of valuing and aspiring to higher levels of education. To value education, students need to perceive that they are welcome, express their ideas and engage meaningfully in each education space they enter. Therefore, ‘pupil voice’ has the potential to become an important influencing factor regarding the degree to which students become self‐regulated learners, value educationand consequently support their aspirations and build their expectations to go on to university. This study examines the role pupil voice plays in building cognitive and emotional engagement, and whether this, in turn, builds desire for further study and expectations for university entry. Pupil voice is operationalised as the extent to which the student feels heard, involved and supported by the school community. Student survey data was collected (N = 542) from a low socioeconomic status region of the southwest corridor of metropolitan Perth, Western Australia. Structural equation modelling substantiated our serial mediation hypothesis. For students, a discernible pupil voice significantly and positively increased cognitive engagement (self‐regulated learning), which increased emotional engagement (valuing education) that, in turn, increased university desires, which led to increased university expectations. The results of this study underscore the importance of policies and practical interventions designed to develop strong student–teacher relationships, where students feel they are both seen and heard.

Assessment of the pest status of Pratylenchus curvicauda and ultrastructural changes in roots of infected wheat and barley

AbstractPratylenchus curvicauda, which was first described in metropolitan Perth in 1991, was recently identified in grain‐growing areas in Western Australia. The biology of this root‐lesion nematode, and especially its pest status, is unknown. We investigated its life cycle and interaction with host plants, because such information is essential for its management. The life cycle took 45 days to complete in a wheat cultivar maintained at 23°C. Over 10 weeks, the nematode multiplied in 26 of 61 genotypes; these host plants were all cereals and included widely grown cultivars of wheat and barley. Eighteen other cereal genotypes and 13 cultivars including canola, chickpea, ryegrass, lupin, soybean, and tomato, sustained the nematodes to different degrees without multiplication. Four cover crops were not suitable hosts. The patterns of attraction of the nematodes and penetration into roots of the host and tolerant plants were similar. The nonhosts attracted fewer nematodes, none of which penetrated the roots. Browning of infected roots was atypical—it occurred late in some roots, 55 days after inoculation, and in the presence of a fungus. The nematodes were confined to, and fed from, cortical cells. The ultrastructure of infected wheat and barley cells showed typical signs of damage caused by Pratylenchus spp. and included cell disorganization and lack of membrane integrity, disintegration of cytoplasm, hypertrophy of some nuclei, and deposition of tannin‐like granules. This detailed characterization of P. curvicauda–host interaction indicates the nematode is likely to be a pest of major crops, and attention should be given to its management.

Patients with multiple myeloma over a large catchment of 2.5 million square kilometres: a Western Australia retrospective survival review.

Multiple myeloma is an incurable malignancy of plasma cells. We retrospectively reviewed the survival outcomes of patients with multiple myeloma in Western Australia (WA) public hospitals over a 10-year period. We did not detect a difference in survival between patients residing the metropolitan Perth and regional areas, despite a paucity of haematology services in regional WA due to low population density in a large geographic area. Patients with R-ISS Stage 3 had the poorest survival in our cohort with median survival of 24 months.

Over the limit? Testing non-linear associations between alcohol outlets and young adults' alcohol consumption.

By specifying a threshold at which the number of liquor licences has the most impact on local populations, authorities can work to restrict licence approvals and help prevent alcohol-related harm. Raine Study Generation 2 participants reported their alcohol intake at 22 years (n = 843) and liquor licences within 1600 m of participants' homes were mapped. Analyses examined associations between licences (all licences, on-premise licences, liquor stores) and alcohol intake (g ethanol per day). Two models were fitted: (i) forced a straight-line relationship; and (ii) allowed a curved relationship via restricted cubic splines. The straight-line and curved models showed significant relationships with all licences (P = 0.002 and P = 0.002 respectively) and on-premise licences (P = 0.006 and P = 0.01 respectively), but not liquor stores (P = 0.065 and P = 0.13 respectively). The straight-line model indicated that alcohol consumption increased, on average, by 0.15 g per day for each additional licence and 0.17 g per day for each additional on-premise licence. The curved model indicated that consumption increased by around 0.4 g per day for each additional licence from 0 to 10, but increases were negligible for additional licences beyond 10. The curved model provided a better overall fit to the data than the straight-line model (R2 9.52% vs. 9.18%), but the improvement in fit did not quite reach statistical significance (P = 0.08). The curvature was similar, but less pronounced for on-premise licences (R2 9.11% vs. 8.95%; P = 0.23). Results suggest a possible saturation point at which additional licences have a smaller effect on the alcohol intake of 22-year-olds living in metropolitan Perth.

A Graph Automorphic Approach for Placement and Sizing of Charging Stations in EV Network Considering Traffic

This paper proposes a novel graph-based approach with automorphic grouping for the modelling, synthesis, and analysis of electric vehicle (EV) networks with charging stations (CSs) that considers the impacts of traffic. The EV charge demands are modeled by a graph where nodes are positioned at potential locations for CSs, and edges represent traffic flow between the nodes. A synchronization protocol is assumed for the network where the system states correspond to the waiting time at each node. These models are then utilized for the placement and sizing of CSs in order to limit vehicle waiting times at all stations below a desirable threshold level. The main idea is to reformulate the CS placement and sizing problems in a control framework. Moreover, a strategy for the deployment of portable charging stations (PCSs) in selected areas is introduced to further improve the quality of solutions by reducing the overshooting of waiting times during peak traffic hours. Further, the inherent symmetry of the graph, described by graph automorphisms, are leveraged to investigate the number and positions of CSs. Detailed simulations are performed for the EV network of Perth Metropolitan in Western Australia to verify the effectiveness of the proposed approach.

Increasing Food Expenditure in Long Day-care by an Extra $0.50 per Child/Day Would Improve Core Food Group Provision.

Early childhood education and care services are a significant feature of Australian family life, where nearly 1.4 million children attended a service in 2019. This paper reports on the cost of food provided to children in long day-care (LDC) services and extrapolates expenditure recommendations to support food provision compliance. A cross-sectional audit of LDC services in metropolitan Perth was conducted to determine food group provision by weighing raw ingredients of meal preparation—morning tea, lunch, and afternoon tea (MT, L, AT). Ingredients were costed at 2017 online metropolitan pricing from a large supermarket chain. Across participating services, 2 days of food expenditure per child/day ranged between $1.17 and $4.03 across MT, L, AT, and averaged $2.00 per child/day. Multivariable analysis suggests that an increase of $0.50 per child/day increases the odds of a LDC service meeting >50% of Australian Dietary Guideline (ADG) recommendations across ≥4 core food groups by fourfold (p = 0.03). Given the fact that the literature regarding food expenditure at LDC services is limited, this study provides information about food expenditure variation that impacts planning and provision of nutritionally balanced menus recommended for children. An average increase of food expenditure of $0.50 per child/day would increase food provision compliance.

A Data-Driven Approach to Exploring Future Land Use and Transport Scenarios: The Online What If? Tool

ABSTRACTIn an era of rapid urbanization, there is a need for data-driven tools to guide long-term strategic planning. Online What If? (OWI) is a planning support system (PSS) that helps inform strategic planners about the impact of population growth and other socioeconomic factors will have on the future growth of cities. This research presents its application in metropolitan Perth with a two-part case study, demonstrating a first comprehensive application of the tool. First, OWI tests five scenarios for urban growth through the year 2050, allocating residential land use. Next, OWI alters land use allocations to align residential development with high frequency public transit, while also allocating commercial land use to support higher residential densities. Together, these data-driven scenarios inform city planners and policy makers in guiding the long-term, sustainable growth of Perth. The paper concludes with a review of OWI’s strengths, weaknesses and possibilities for continual development.

Vegetation trends associated with urban development: The role of golf courses.

Globally, cities are growing rapidly in size and density and this has caused profound impacts on urban forest ecosystems. Urbanization requiring deforestation reduces ecosystem services that benefit both city dwellers and biodiversity. Understanding spatial and temporal patterns of vegetation changes associated with urbanization is thus a vital component of future sustainable urban development. We used Landsat time series data for three decades from 1988 to 2018 to characterize changes in vegetation cover and habitat connectivity in the Perth Metropolitan Area, in a rapidly urbanising Australian biodiversity hotspot, as a case study to understand the impacts of urbanization on urban forests. Moreover, as golf courses are a major component in urban areas, we assessed the role of golf courses in maintaining vegetation cover and creating habitat connectivity. To do this we employed (1) land use classification with post-classification change detection, and (2) Morphological Spatial Pattern Analysis (MSPA). Over 17,000 ha of vegetation were cleared and the area of vegetation contributing to biodiversity connectivity was reduced significantly over the three decades. The spatial patterns of vegetation loss and gain were different in each of the three decades (1988-2018) reflecting the implementation of urban planning. Furthermore, MSPA analysis showed that the reduction in vegetation cover led to habitat fragmentation with a significant decrease in the core and bridge classes and an increase in isolated patches in the urban landscape. Golf courses played a useful role in maintaining vegetation cover and contributing to connectivity in a regional biodiversity hotspot. Our findings suggest that for future urban expansion, urban planning needs to more carefully consider the impacts of deforestation on connectivity in the landscape. Moreover, there is a need to take into consideration opportunities for off-reserve conservation in smaller habitat fragments such as in golf courses in sustainable urban management.

Effect of sex and age on survival and neurological outcome in patients admitted to intensive care after out-of-hospital cardiac arrest

Introduction: Studies report varying effects of sex and age on survival and neurological outcome in patients admitted to hospital following an out-of-hospital cardiac arrest (OHCA). Objectives/Aims: To determine if patient sex or age is associated with survival or good neurological outcome at hospital discharge in adult OHCAs of medical aetiology admitted to tertiary intensive care units in Western Australia. Methods: We conducted a retrospective medical record review of OHCA patients >18 years attended by St John WA in metropolitan Perth and admitted to four tertiary intensive care units, January 2012 to December 2017. Adjusted multivariable logistic regression analysis was used to identify patient and pre-hospital factors associated with survival or good neurological outcome (Cerebral Performance Category Scale [CPC]<3) at hospital discharge. Results: Of 8016 OHCAs of medical aetiology attended by St John WA, 3997/8016 (49.9%) had resuscitation attempted with 502/3997 (12.6%) admitted to intensive care. Of these, 144 (29%) were female, mean age was 58.8 years, 313 (62.4%) had an initial shockable rhythm, 284 (56.6%) were witnessed, 349 (69.5%) received bystander cardiopulmonary resuscitation, 79 (15.7%) were admitted to hospital with ongoing cardiopulmonary resuscitation. Of the 237/502 (47.2%) hospital survivors, 215/237 (90.7%) had a CPC<3. Differences in outcomes between the sexes were not statistically significant after multivariable adjustment (survival to hospital discharge p=0.46; CPC<3 p=0.06). Compared with patients 18-44 years, only those >65 years had significantly lower survival (odds ratio 0.32; 95% confidence interval 0.17-0.57); however CPC<3 was not significantly different between age groups. Patients aged >65 years were also less likely to survive (odds ratio 0.18; 0.08-0.39) when analysis was restricted to those with initial shockable rhythm. Conclusions: Older patients (>65 years) were less likely to survive to hospital discharge after OHCA, but differences in OHCA outcomes between men and women were accounted for by differences in underlying prognostic factors.

Overcoming the misrepresentation of disease burden associated with single aggregation choropleth maps through combining information from many aggregations

BackgroundAccurate disease mapping based on spatiotemporal data is an important aspect of public health surveillance, targeting interventions, and health service planning. This is achieved by public health surveillance organisations around the world through the construction of choropleth maps based on single spatiotemporal aggregations of finer resolution data. However, such maps are undermined by their dependence on the spatiotemporal units used. This dependence is described by the related modifiable areal and temporal unit problems (MAUP; MTUP), also known as change of support problems (COSPs).&#x0D; AimTo accurately map disease.&#x0D; MethodsUsing ischaemic stroke admissions and mental health-related ED presentations in metropolitan Perth between 2013 and 2016 as exemplars, we present a novel zonation overlay approach for disease mapping. This method involves aggregating fine resolution spatial data numerous times instead of just once, using the automated zonation construction software AZTool.&#x0D; Results Through implementing the zonation overlay method in combination with a rolling window of time, both the MAUP and the MTUP may be overcome in the context of disease mapping. Furthermore, the AZTool zonations act as a geographical encryption key, allowing fine resolution, precise maps to be constructed while protecting the privacy of individuals.&#x0D; ConclusionHealth surveillance organisations continue to produce single aggregation choropleth maps of disease, without acknowledging their limitations except in rare cases. Producing such maps and suggesting they should guide policy makers, while being aware of but not acknowledging the impact of COSPs, could be described as scientific malfeasance. However, assuming that most researchers producing such maps are not intending to mislead, we must conclude that COSPs are poorly understood and their impact underestimated. The zonation overlay method we describe can help alleviate the consequences of this continued practice.

A comparison of major trauma patient transport destination in metropolitan Perth, Western Australia

BackgroundDespite evidence of a lower risk of death, major trauma patients are not always transported to Trauma Centres. This study examines the characteristics and outcomes of major trauma patients between transport destinations. MethodsA retrospective cohort study of major trauma patients (Injury Severity Score >15) transported by ambulance was undertaken. Cases were divided into transport destination groups: (1) Direct, those transported to the Trauma Centre directly from the scene; (2) Indirect, those transported to another hospital prior to Trauma Centre transfer and (3) Non-transfers, those transported to a non-Trauma Centre and never subsequently transferred. Median and interquartile range (IQR) were used to describe the groups and differences were assessed using the Kruskal–Wallis test for continuous variables and Pearson chi-square for categorical. ResultsA total of 1625 patients were included. The median age was oldest in the non-transfers cohort (72 years IQR 46–84). This group had the highest proportion of falls from standing and head injuries (n = 298/400, 75%, p < 0.001). The non-transfers had the highest proportion of 30-day mortality (n = 134/400, 34%). ConclusionsThere were significant differences between the groups with older adults, falls and head injuries over-represented in the non-transfer group. Considering the ageing population, trauma systems will need to adapt.

Maternity care of women affected by female genital mutilation/cutting: An audit of two Australian hospitals

BackgroundPregnant women affected by female genital mutilation/cutting are at risk of adverse maternal outcomes compared to unaffected women, and sometimes require procedures to facilitate giving birth that midwives and doctors do not routinely perform. These women require culturally sensitive care. Current health professional literature provides evidence that midwives and doctors need further knowledge and training in this area. AimsThis audit aimed to describe the demographic characteristics of pregnant women with female genital mutilation/cutting giving birth at two Perth maternity units, in addition to assessing health provider compliance with the local female genital mutilation/cutting Clinical Guideline. Materials and methodsThe clinical database used by public maternity units in Western Australia was used to identify affected women who gave birth during 2014 at King Edward Memorial Hospital or Osborne Park Hospital. Demographic characteristics and information about antenatal care and maternal outcomes were collected. Results53 women fulfilled the audit criteria. Prevalence of pregnant women with female genital mutilation/cutting varied from 0.33% to 2.18% between the two units. Compliance with the Female Genital Mutilation/Cutting Clinical Guideline was generally suboptimal. While no woman was deinfibulated antenatally, 26% of women required intrapartum deinfibulation to give birth. ConclusionsWomen with female genital mutilation/cutting make up more than 2% of the antenatal population in some Perth metropolitan maternity units. Health care provider knowledge of, and compliance with, the Female Genital Mutilation/Cutting Clinical Guideline was poor in the two units studied. It appears that healthcare professionals need more education and training to provide affected women with the best care.

Non-typhoidal Salmonella contamination in egg shells and contents from retail in Western Australia: Serovar diversity, multilocus sequence types, and phenotypic and genomic characterizations of antimicrobial resistance

In recent years, the number of human salmonellosis cases in Western Australia (WA) has increased more dramatically than in any other Australian state. In 2017, the number of cases in WA was more than double the five-year average, and eggs had emerged as the key culprit for several Salmonella foodborne disease outbreaks. To better understand such an epidemiologically intriguing situation, our research goal was to investigate the prevalence, serovar diversity, multilocus sequence types, and antimicrobial resistance of non-typhoidal Salmonella contamination in retail eggs produced and sold in WA. A total of 200 visually clean and intact retail egg samples (each containing a dozen eggs) were purchased for one year (2017–2018) from supermarkets in metropolitan Perth, the capital of WA. For each sample, the contents and shells of the 12 eggs were separately pooled and cultured according to standard methods. Overall, Salmonella was detected in 11.5% (23/200) of the tested egg samples. Salmonella was isolated from 4.5% (9/200) and 3% (6/200) of eggshells and egg contents, respectively. In 4% (8/200) of the samples, Salmonella was recovered from both eggshell and egg contents. Isolates from positive retail egg samples were serotyped as either S. Typhimurium (52.2% [12/23]) or S. Infantis (39.1% [9/23]). Both serotypes were concurrently recovered from two different retail egg samples. We retained a set of both S. Typhimurium (n = 29) and S. Infantis (n = 12) isolates from all Salmonella-positive retail packs (n = 23) for further characterization. Only two (S. Typhimurium) isolates showed resistance to ampicillin, of which one carried β-lactamase resistance gene blaTEM-1b. The remaining isolates (39/41) were susceptible to all 14 antimicrobials included in the minimum inhibitory concentrations (MICs) testing panel. Multilocus sequence typing and serotyping were perfectly mirrored, as all S. Typhimurium isolates were characterized as sequence type (ST)-19, and all S. Infantis isolates were ST-32. This study points to the noteworthy Salmonella prevalence rate in retail egg samples in WA. Our results illustrate minimal public health risks arising from antimicrobial resistance Salmonella from Australian eggs.

General practitioners’ perceptions of their communication with Australian Aboriginal patients with acquired neurogenic communication disorders

ObjectiveAboriginal people have high rates of stroke and traumatic brain injury (TBI), often with residual, chronic communication deficits and multiple co-morbidities. This study examined general practitioners’ (GPs’) perceptions of their communication with Aboriginal patients with acquired communication disorders (ACD) after brain injury. Effective communication underpins good care but no previous research has explored this specific context. MethodsA qualitative descriptive approach was employed using interviews and focus groups with 23 GPs from metropolitan Perth and five regional sites in Western Australia. Data were analysed thematically. ResultsGPs reported low visibility of Aboriginal patients with ACD in their practices, minimal training on neurogenic ACD, and difficulty distinguishing ACD from cultural-linguistic factors. They had few communication resources, and depended on families and Aboriginal Health Workers to assist in interactions. They rarely used formal interpreting services or referred to speech pathology. They reported communication (dis)ability having low priority in consultations. ConclusionGPs report difficulty recognising ACD and their lack of prioritising assessment and treatment of communication ability after brain injury potentially compounds the disadvantage and disempowerment experienced by many Aboriginal people. Practice implicationsGPs require further communication and cultural training. Improved access to speech pathology and formal interpreting services would be beneficial.

Determining spatial patterns in recreational catch data: a comparison of generalized additive mixed models and boosted regression trees

Abstract Marine recreational fisheries (MRFs) are often highly spatially heterogenous, with effort concentrated into small areas, and fisheries spanning large environmental gradients. However, spatially resolved catch data is rarely collected in MRFs, preventing the study of spatial heterogeneity in catch. This study uses recreational catch reported in 10 × 10 nm blocks across eight degrees of latitude in Western Australia to map spatial predictions of the probability of a recreational catch on an average trip for two key species: West Australian dhufish (Glaucosoma hebraicum) and snapper (Chrysophrys auratus). Two spatial modelling techniques are compared for the analysis, generalized additive mixed models (GAMMs) and boosted regression trees (BRTs). We find that BRTs outperform GAMMs, but performance gains are small. We also find marked spatial variations in recreational catch probabilities: high catches of dhufish are found in the north of the study area, and low catches in the Perth Metropolitan area and in the south; snapper catches are highest in the north and low in the south. These patterns are used to identify important spatial processes in the fishery. The analysis also suggests that modelling approach (GAMMs or BRTs) has only a minor effect on outcomes of spatial catch analysis in MRFs.

Long-term Exposure to Low Air Pollutant Concentrations and the Relationship with All-Cause Mortality and Stroke in Older Men.

Long-term air pollution exposure has been associated with increased risk of mortality and stroke. Less is known about the risk at lower concentrations. The association of long-term exposure to PM2.5, PM2.5 absorbance, NO2, and NOx with all-cause mortality and stroke was investigated in a cohort of men aged ≥ 65 years who lived in metropolitan Perth, Western Australia. Land use regression models were used to estimate long-term exposure to air pollutants at participant's home address (n = 11,627) over 16 years. Different metrics of exposure were assigned: baseline; year before the outcome event; and average exposure across follow-up period. The Mortality Register and Hospital Morbidity Data from the Western Australia Data Linkage System were used to ascertain mortality and stroke cases. Hazard ratios (HRs) and 95% confidence intervals were estimated using Cox proportional hazard models, adjusting for age, smoking, education, and body mass index for all-cause mortality. For fatal and hospitalized stroke, the models included variables controlled for all-cause mortality plus hypertension. Fifty-four percent of all-participants died, 3% suffered a fatal stroke, and 14% were hospitalized stroke cases. PM2.5 absorbance increased the risk of all-cause mortality with adjusted HR of 1.12 (1.02-1.23) for baseline and average exposures, and 1.14 (1.02-1.24) for past-year exposure. There were no associations between PM2.5 absorbance, NO2, and NOx and stroke outcomes. However, PM2.5 was associated with reduced risks of fatal stroke. Long-term exposure to PM2.5 absorbance was associated with all-cause mortality among older men exposed to low concentrations; and exposure to PM2.5 was associated with reduced risk of fatal stroke.

Anxiety and alcohol in the working-age population are driving a rise in mental health-related emergency department presentations: 15 year trends in emergency department presentations in Western Australia.

To evaluate age, gender and disease-specific trends in ED for mental health presentations over 15 years. The study population consisted of residents of metropolitan Perth, Western Australia, presenting to Perth ED between 1 July 2002 and 30 June 2017. Population rates of mental health-related ED presentations per year were calculated. Rates of mental health ED presentations are significantly increasing in the working-age population for those with stress and anxiety-related diagnoses, particularly in younger females, and also for alcohol-related presentations for those aged 10-49 years, particularly in males. The present study demonstrates that increased rates of mental health-related ED presentations are driven by increased rates of presentation for stress and anxiety-related and alcohol-related presentations in both genders across the working-age population.