Southern Tasmania Research Articles

Adverse drug reactions in older people following hospitalisation: a qualitative exploration of general practitioners' perspectives.

Older people have greater comorbidity and medication burden. Adverse drug reactions occur in up to 30% of older people within one month of hospital discharge. General practitioners are key stakeholders in transitions of care from hospital to the community. The study aimed to explore general practitioner perspectives of adverse drug reactions in older people after hospitalisation, investigating the medication-related issues encountered and possible approaches to reduce the risk. An invitation to participate in the study was sent to general practitioners in Southern Tasmania, Australia. A semi-structured interview occurred in person at their practice or online. The questions covered experiences with managing medication in older people after hospital discharge, challenges and risks involving adverse drug reactions and suggestions to prevent adverse drug reactions. The interviews were transcribed and analysed through thematic analysis. Twelve general practitioners were interviewed, revealing four themes describing challenges, including (i) complex patients and acceptance of risk, (ii) patient confusion and decline in hospital, (iii) time taken to manage older patients and (iv) communication challenges. Three themes describing recommendations were identified, including (i) clear communication on discharge, (ii) patient involvement and (iii) roles for pharmacists. Prevention of adverse drug reactions after hospital discharge may require clear and timely communication to general practitioners, patients and families to be educated and empowered to help manage their own health and risk, and pharmacists to support both patients and general practitioners in managing the risks.

Impact of pre-harvest application of 1-methylcyclopropene (1-MCP) on fruit quality, physiological disorders and respiration rate of ‘Scilate’ apple

The ethylene inhibitor 1-methylcyclopropene (1-MCP) is widely used in the apple industry as a post-harvest fumigation application to slow down the ripening process and maintain fruit quality during storage. With the development of a sprayable formulation (Harvista™, Agrofresh Inc, USA), it is becoming increasingly common in the apple industry to apply 1-MCP as a pre-harvest spray. This study investigated the impact of pre-harvest 1-MCP applied 1 week prior to harvest as a foliar application at 11.4 L ha−1 in 1000 L water, on the quality and respiration rate of ‘Scilate’ apples grown in the Huon Valley, Southern Tasmania, Australia. Two trials were undertaken, trial 1 examined fruit quality, flesh browning (FB) and fruit softening in 1-MCP treated and untreated fruit while trial 2 compared the respiration rate of 1-MCP treated and untreated fruit. Despite no effect on fresh fruit quality attributes, pre-harvest spray application of 1-MCP influenced post-harvest fruit quality, storability, and respiration rate of apples. Fruit treated with 1-MCP showed higher malic acid concentration (1.2 g L−1 vs 0.9 g L−1) and lower juice pH (4.6 vs 4.9) even after 7.5 months of regular air cold-storage along with a six-fold reduction in fruit softening in comparison to untreated fruit (2% vs 13%). Pre-harvest treatment of 1-MCP reduced respiration rate by 32%, and incidence of CO2 injury by over 40%. The incidence of radial type (senescent related) FB was reduced by 100%. A significant proportion of treated apples still suffered from severe CO2 injury. This study has demonstrated that pre-harvest application of 1-MCP to ‘Scilate’ fruit can be useful in maintaining long-term fruit quality during storage, reducing respiration rate, and lowering the incidence of FB in general. However, the risk of severe CO2 injury remains, especially with larger fruit harvested from trees with lighter crop loads.

A Trial of a Virtual Fence to Mitigate Roadkill on an Unsealed Rural Road in Tasmania, Australia.

A commercial roadkill Virtual Fence (VF) mitigation device (iPTE Traffic Solutions) was used in a field trial to test its effectiveness, for which previously published results have been inconsistent, along a 4.9 km segment of road on Bruny Island, Tasmania. A total of 585 days of monitoring roadkill by species was conducted, with six sections that were alternatively switched on or off according to the Crossover and Multiple Before-After-Control-Impact (MBACI) experimental designs that divided monitoring into "off-on" then "on-off" periods. Aggregate counts, for each period by section combination, from daily counts of Tasmanian pademelons (Thylogale billardierii) were modelled, with a total count of 222. The statistical analysis used the MBACI design to estimate the VF effect using a log-odds ratio parameter (LORP) while accounting for local spatio-temporal effects. Both versions of the analysis, either averaged over the three spatial replicates (paired sections) or two temporal replicates (blocks), showed no statistically significant effect of the VF, judged as an LORP estimate not sufficiently below zero. Corresponding percentage reduction estimates of 9% and 16% were derived from the LORP. The corresponding statistical power required to detect a nominal significant reduction of 50% in rate was 0.5 and 0.6, respectively. This study confirms the results from a similar previous field trial in southern Tasmania that this VF is likely to lead to, if anything, only a minor reduction in roadkill.

Patient and carer experiences of living with multiple myeloma and myelodysplastic syndrome.

Multiple myeloma (MM) and myelodysplastic syndrome (MDS) are treatable but incurable conditions that can substantially impact the daily lives of people living with these conditions and their carers. We sought to understand the experience of people living with and carers affected by these conditions in Tasmania, a regional area of Australia. Exploratory qualitative study. People living with MM or MDS or their carers in Southern Tasmania were recruited by a haematology nurse and invited to participate in focus groups. Data collection was by groups held online and face-to-face in 2022. Thematic analysis was used. Ten groups were held with 48 participants (n=23 with MM, n=9 with MDS, n=16 carers). Key themes arising from focus groups with people living with MM/MDS were (1) Relationships and Support; (2) Positive Attitude; (3) Perception of Condition; and (4) Symptoms and Comorbidities. Some people with MM/MDS had to take on a caring role for their carer due to carer illness. Key themes arising from carer focus groups included (1) Supportive Relationships; (2) Accommodating Change; and (3) Own Needs. Not all carers viewed their caring role as burdensome. Future work should consider what supports are required for patients acting as carers, and carer burden should not be assumed.

Two new species in the spider genus Nanometa (Araneae: Tetragnathidae: Nanometinae) from Tasmania

Two new species in the orb-weaving spider genus Nanometa Simon, 1908 are described, N. ilanejzykowiczi sp. nov. and N. cerastes sp. nov. (family Tetragnathidae Menge, 1866), elevating the number of described Australian species to eight. Both new species have so far only been recorded from Hartz Mountains National Park, southern Tasmania, at about 1,200 metres a.s.l., where two other species, N. tasmaniensis Álvarez-Padilla, Kallal & Hormiga, 2020 and N. tetracaena Álvarez-Padilla, Kallal & Hormiga, 2020 also occur.

Long-term stability of temperate Australian wet forest-moorland mosaics despite recurrent fires associated with late Holocene climate change

ContextThe primary factors(s) responsible for the maintenance of Alternative biome states (ABS) in world forest biomes remains unclear and debatable, partly due to insufficient long-term ecological data from suitable ecosystem sites. The occurrence of moorland in southern and western Tasmanian wet temperate forest presents a suitable setting to test for ABS and understand the main stabilizing factors of ABS.ObjectivesWe use a palaeoecological approach to test for ABS and identify the degree of vegetation change and the effect of climate change and fire occurrence associated with ABS in southern Tasmania.MethodsSediment sequence from sink-hole lake in a forest and nearby pond in southern Tasmania were analysed for pollen and charcoal to reconstruct histories of forest, moorland and fire in the Tasmanian Wilderness World Heritage Area (TWWHA). Reconstructions were compared to palaeoclimate record.ResultsMoorland and forest in southern Tasmania have occupied the same habitat for at least the last 2600 years, and neither past climate change nor fire occurrence affected the stability of the vegetation mosaic. We suspect that localized environmental settings, such as topography and edaphic conditions are the primary stabilizing factors of the forest-moorland mosaics.ConclusionsThe observed stable vegetation mosaics in our study is contrary to the dominant ecological paradigm of landscape dynamics currently used to manage the TWWHA, and there is a need to refine the ecological basis of fire management in the area. Similar targeted palaeoecological studies are needed to fully understand the underlying factors responsible for the persistence of treeless vegetation in world forest biomes.

Two new species of crane fly (Diptera: Limoniidae) from Tasmania, Australia

Two new species of Australian crane fly are described, illustrated and with COI sequences included: Gynoplistia (Gynoplistia) lutruwita Billingham & Theischinger sp. nov., and Molophilus (Molophilus) serricauda Billingham & Theischinger sp. nov., both from the Huon Valley region of southern Tasmania. Their affinities with other known Australian species are discussed.

Acceptability of a peer-led self-management program for people living with chronic obstructive pulmonary disease in regional Southern Tasmania in Australia: A qualitative study.

People living with chronic obstructive pulmonary disease (COPD) in regional communities experience a higher disease burden and have poorer access to support services. This study sought to investigate the acceptability of a peer-led self-management program (SMP) in regional Tasmania, Australia. This descriptive qualitative study, underpinned by interpretivism used semi-structured one-to-one interviews to gather data to explore COPD patients' views of peer-led SMPs. Purposeful sampling recruited a sample of 8 women and 2 men. Data was analysed using a thematic approach. The three final themes, 'Normality and Living with the disease', a 'Platform for sharing' and 'Communication mismatch' suggest that peer-led SMPs could offer an opportunity to share experiences. The themes also suggest that COPD often manifested as a deviation from 'normal life'. Communication was often felt to be ambiguous leading to tension between the health experts and people living with the condition. Peer-led SMP has the potential to provide the much-needed support for people living with COPD in regional communities. This will ensure that they are empowered to live with the condition with dignity and respect. Benefits of exchanging ideas and socialisation should not be ignored and may enhance sustainability of SMPs.

Health and medical professionals’ antenatal HIV testing practices and perceived barriers to routine testing in Tasmania, Australia: a qualitative study

ObjectivesThis study sought to explore health and medical professionals’ antenatal HIV testing practices and the perceived barriers to routine testing in Tasmania, Australia.DesignThis qualitative study undertook a Foucauldian-informed discourse analysis...

Molecular systematic analysis demonstrates that the threatened southern bell frog, Litoria raniformis (Anura: Pelodryadidae) of eastern Australia, comprises two sub-species

In south-eastern Australia, the pelodryadid Litoria aurea Group (sensu Tyler & Davies 1978) comprises three species: Litoria aurea (Lesson, 1829), Litoria raniformis (Keferstein, 1867), and Litoria castanea (Steindachner, 1867). All three species have been subject to declines over recent decades and taxonomic uncertainty persists among populations on the tablelands in New South Wales. We address the systematics of the Group by analysing mitochondrial and nuclear DNA sequences to assess divergence in the Litoria raniformis from across its current range in New South Wales (NSW), Victoria, South Australia (SA) and Tasmania. We also included samples of Litoria castanea from a recently rediscovered population in the southern tablelands of NSW. Our phylogenetic and population genetic analyses show that Litoria raniformis comprises northern and southern lineages, showing deep mitochondrial DNA sequence divergence (7% net average sequence divergence) and can be diagnosed by fixed allelic differences at more than 4,000 SNP loci. Samples of the northern lineage were collected from the Murray-Darling Basin while those of the southern lineage were collected from south-eastern South Australia, southern and south-eastern Victoria and Tasmania. Analysis of the morphology and bioacoustics did not unequivocally delineate the two lineages. The presence of a hybrid backcross individual in western Victoria at the northern margin of the southern lineage, leads us to assign sub-species status to the two lineages, L. r. raniformis for the northern lineage and L. r. major for the southern lineage. Our data do not unequivocally resolve the taxonomic status of L. castanea which will require molecular genetic analyses of museum vouchers from those parts of the range where L. castanea and L. raniformis are no longer extant. Our data also suggest that human mediated movement of frogs may have occurred over the past 50 years. Our genotyping of vouchers collected in the 1970s from the Mount Lofty Ranges in South Australia detected mitochondrial haplotypes of both sub-species and SNP analysis showed that a single Tasmanian specimen was a backcross with L. r. raniformis ancestry. Movement of L. r. raniformis into Tasmania and both sub-species into the Mount Lofty Ranges are not likely due to passive movements of animals through agricultural commerce, but due to the attractiveness of the species as pets and subsequent escapes or releases, potentially of the larval life stage.

Crop Load and Thinning Methods Impact Yield, Nutrient Content, Fruit Quality, and Physiological Disorders in ‘Scilate’ Apples

Most apple cultivars produce too many flowers to enable consistent yields of high-quality fruit, thus, crop load management (thinning) is an integral part of orchard management in modern apple cultivation. Crop load is managed by thinning excess flowers and/or fruit from a tree, however ideal targets vary between cultivars. In this two-year study, the effect of thinning methods at different levels of crop load on fruit quality and production, post-harvest storability and physiological disorders, and fruit and leaf nutrient content in ‘Scilate’ apples were investigated in southern Tasmania, Australia. Two thinning methods, artificial bud extinction (ABE) and hand thinning (HT), were compared at three levels of crop load: 3, 6, or 12 fruit cm−2 limb cross-sectional area (LCSA), described as low, medium, and high, respectively. During the second season, all the ABE and HT treatments received additional chemical thinning (CT). The results demonstrated that ABE consistently outperformed HT in terms of improved fruit set, return bloom, and fruit weight. The fruit quality parameters, such as flesh firmness, total soluble solids, dry matter content, malic acid content, and fruit shape, were also improved under the ABE regime, with these positive effects being the clearest in the second season. In general, high-quality fruits were obtained from the low and medium crop loads, while the fruit quality was poor for the high crop load trees, but the low crop load fruit had a slightly higher incidence of internal flesh browning (predominantly radial) and fruit softening after regular atmosphere storage. The crop load also impacted on the fruit and leaf mineral nutrient content, where fruit N, Ca, Mn, and Zn, and leaf N, Fe, Zn, and Cu content increased while fruit and leaf K declined with a higher crop load. High crop load, irrespective of the thinning regime, and HT with a medium crop load, induced severe biennial bearing, whereas, the fruit yield was relatively consistent with ABE, even with a medium crop load. We conclude that ABE with a medium crop load (around six fruit cm−2 LCSA) is an effective method of managing crop load and optimizing the fruit quality in ‘Scilate’ apples.

Impact of Vertical Atmospheric Structure on an Atypical Fire in a Mountain Valley

Wildfires are not only a natural part of many ecosystems, but they can also have disastrous consequences for humans, including in Australia. Rugged terrain adds to the difficulty of predicting fire behavior and fire spread, as fires often propagate contrary to expectations. Even though fire models generally incorporate weather, fuels, and topography, which are important factors affecting fire behavior, they usually only consider the surface wind; however, the more elevated winds should also be accounted for, in addition to surface winds, when predicting fire spread in rugged terrain because valley winds are often dynamically altered by the interaction of a layered atmosphere and the topography. Here, fire spread in rugged terrain was examined in a case study of the Riveaux Road Fire, which was ignited by multiple lightning strikes in January 2019 in southern Tasmania, Australia and burnt approximately 637.19 km2. Firstly, the number of conducive wind structures, which are defined as the combination of wind and temperature layers likely to result in enhanced surface wind, were counted by examining the vertical wind structure of the atmosphere, and the potential for above-surface winds to affect fire propagation was identified. Then, the multiple fire propagations were simulated using a new fire simulator (Prototype 2) motivated by the draft specification of the forthcoming new fire danger rating system, the Australian Fire Danger Rating System (AFDRS). Simulations were performed with one experiment group utilizing wind fields that included upper-air interactions, and two control groups that utilized downscaled wind from a model that only incorporated surface winds, to identify the impact of upper air interactions. Consequently, a detailed analysis showed that more conducive structures were commonly observed in the rugged terrain than in the other topography. In addition, the simulation of the experiment group performed better in predicting fire spread than those of the control groups in rugged terrain. In contrast, the control groups based on the downscaled surface wind model performed well in less rugged terrain. These results suggest that not only surface winds but also the higher altitude winds above the surface are required to be considered, especially in rugged terrain.

Eucalyptus obliqua tall forest in cool, temperate Tasmania becomes a carbon source during a protracted warm spell in November 2017

Tasmania experienced a protracted warm spell in November 2017. Temperatures were lower than those usually characterising heatwaves. Nonetheless the warm spell represented an extreme anomaly based on the historical local climate. Eddy covariance measurements of fluxes in a Eucalyptus obliqua tall forest at Warra, southern Tasmania during the warm spell were compared with measurements in the same period of the previous year when temperatures were closer to average. Compared with previous year, the warm spell resulted in 31% lower gross primary productivity (GPP), 58% higher ecosystem respiration (ER) and the forest switching from a carbon sink to a source. Significantly higher net radiation received during the warm spell was dissipated by increased latent heat flux, while canopy conductance was comparable with the previous year. Stomatal regulation to limit water loss was therefore unlikely as the reason for the lower GPP during the warm spell. Temperatures during the warm spell were supra-optimal for GPP for 75% of the daylight hours. The decline in GPP at Warra during the warm spell was therefore most likely due to temperatures exceeding the optimum for GPP. All else being equal, these forests will be weaker carbon sinks if, as predicted, warming events become more common.

Predicting spatial and seasonal patterns of wildlife–vehicle collisions in high-risk areas

Context Vehicle collisions with wildlife can injure or kill animals, threaten human safety, and threaten the viability of rare species. This has led to a focus in road-ecology research on identifying the key predictors of ‘road-kill’ risk, with the goal of guiding management to mitigate its impact. However, because of the complex and context-dependent nature of the causes of risk exposure, modelling road-kill data in ways that yield consistent recommendations has proven challenging. Aim Here we used a multi-model machine-learning approach to identify the spatio-temporal predictors, such as traffic volume, road shape, surrounding vegetation and distance to human settlements, associated with road-kill risk. Methods We collected data on the location, identity and wildlife body size of each road mortality across four seasons along eight roads in southern Tasmania, a ‘road-kill hotspot’ of management concern. We focused on three large-bodied and frequently affected crepuscular Australian marsupial herbivore species, the rufous-bellied pademelon (Thylogale billardierii), Bennett’s wallaby (Macropus rufogriseus) and the bare-nosed wombat (Vombatus ursinus). We fit the point-location data using ‘lasso-regularisation’ of a logistic generalised linear model (LL-GLM) and out-of-bag optimisation of a decision-tree-based ‘random forests’ (RF) algorithm for optimised predictions. Results The RF model, with high-level feature interactions, yielded superior out-of-sample prediction results to the linear additive model, with a RF classification accuracy of 84.8% for the 871 road-kill observations and a true skill statistic of 0.708, compared with 61.2% and 0.205 for the LL-GLM. The lasso rejected road visibility and human density, ranking roadside vegetation type and presence of barrier fencing as the most influential predictors of road-kill locality. Conclusions Forested areas with no roadside barrier fence along curved sections of road posed the highest risk to animals. Seasonally, the frequency of wildlife–vehicle collisions increased notably for females during oestrus, when they were more dispersive and so had a higher encounter rate with roads. Implications These findings illustrate the value of using a combination of attributive and predictive modelling using machine learning to rank and interpret a complexity of possible predictors of road-kill risk, as well as offering a guide to practical management interventions that can mitigate road-related hazards.

Healthcare Providers' Perceptions of Potentially Preventable Rural Hospitalisations: A Qualitative Study.

Potentially preventable hospitalisations (PPHs) are common in rural communities in Australia and around the world. Healthcare providers have a perspective on PPHs that may not be accessible by analysing routine patient data. This study explores the factors that healthcare providers believe cause PPHs and seeks to identify strategies for preventing them. Physicians, nurses, paramedics, and health administrators with experience in managing rural patients with PPHs were recruited from southern Tasmania, Australia. Semi-structured telephone interviews were conducted, and reflexive thematic analysis was used to analyse the data. Participants linked health literacy, limited access to primary care, and perceptions of primary care services with PPH risk. The belief that patients did not have a good understanding of where, when, and how to manage their health was perceived to be linked to patient-specific health literacy challenges. Access to primary healthcare was impacted by appointment availability, transport, and financial constraints. In contrast, it was felt that the prompt, comprehensive, and free healthcare delivered in hospitals appealed to patients and influenced their decision to bypass rural primary healthcare services. Strategies to reduce PPHs in rural Australian communities may include promoting health literacy, optimising the delivery of existing services, and improving social support structures.

Detrital zircon ages, provenance and tectonic evolution in the early Paleozoic of Tasmania and Waratah Bay, Victoria

The provenance of the upper Cambrian to Upper Ordovician sedimentary rocks of Tasmania and Waratah Bay in southern Victoria provides information about the complex and dynamic tectonic environment present during their deposition. This paper uses U–Pb detrital zircon data to constrain stratigraphic comparisons and tectonic reconstructions of these rock sequences. Multivariate statistics are used to investigate the similarity between the U–Pb ages and quantify the disparity among different samples from various locations. In western and central Tasmania, the Tyennan region supplied most detrital zircons during the late Cambrian and Early Ordovician. The overlying Middle Ordovician Pioneer Sandstone records a switch in provenance with zircons derived from the Mount Read Volcanics (MRV) mixed with zircons similar to those from continental-derived Paleozoic sedimentary rocks deposited throughout east Gondwana. The Middle to Upper Ordovician Gordon Group in western and central Tasmania lacks detrital zircons younger than 1.2 Ga, which indicates a return to a local provenance from Precambrian rocks. In southern Tasmania, the switch to zircons derived from the MRV and east Gondwana-like sources occurred earlier within the Cambrian Deadmans Bay Formation, which is dominated by the east Gondwana Paleozoic zircon age signature. In the East Tasmania Terrane, Ordovician sedimentary rocks from Lefroy have detrital zircon populations dominated by Neoproterozoic and earliest Paleozoic sources similar to the Ordovician sedimentary rocks in the Lachlan Orogen. In southern Victoria, the Bear Gully Chert from Waratah Bay exhibit both Tyennan and distal Gondwana detrital sources. The switching of detrital zircon sources in the west Tasmanian sedimentary sequences implies the docking of Tasmania with mainland Australia during the Cambrian Tyennan Orogeny. The arrival of the distal zircons into these basins occurred at different times in the different areas, reflecting a complex local topography and paleogeography. Key Points Paleozoic sedimentary rocks in Tasmanian exhibit multisource detrital U–Pb age signatures that change over time, implying tectonic activity during their deposition. Paleozoic sedimentary rocks in northeastern Tasmania show Gondwana-wide detrital signatures similar to Lachlan Orogen. The Ordovician Bear Gully Chert at Waratah Bay in southern Victoria shows mixed Tasmanian and distal Gondwana detrital populations. The change in detrital zircon signature in western Tasmania suggests that VanDieland docked with the Australian continent during the Cambrian Tyennan Orogeny.

Manipulating Nitrogen and Water Resources for Improved Cool Climate Vine to Wine Quality

Low yeast assimilable nitrogen (YAN) concentrations (&lt;140 mg/N/L) can produce wines with inferior aroma and flavor, regardless of supplemental nitrogen (N) additions in the winery. The impact of doubling commercial field N and irrigation rates was explored in <i>Vitis vinifera</i> L. cv. Chardonnay and Pinot noir over three growing seasons (2016 to 2019) in Southern Tasmania, Australia, to improve YAN concentrations and observe the concurrent influence on vine canopy, yield, and grape and wine composition. Six combinations of irrigation and N rates were applied to 20 vines for each treatment combination and replicated across both cultivars. The treatments included the standard irrigation rate (~530 L/vine/year) / control N (0 kg/N/ha/year) rate, standard irrigation / standard commercial N rate (~18 kg/N/ha/year), standard irrigation / double commercial N rate (~36 kg/N/ha/year), double irrigation rate (~1060 L/vine/year) / control N, double irrigation / standard N, and double irrigation / double N. Analysis of variance was used to determine main treatment effects and treatment interactions of the measured variables for a subset of the vine population in each growing season. Increasing N rate improved YAN concentrations in both cultivars in two of three growing seasons, with the double N rate associated with increasing YAN to acceptable (&gt;140 mg/N/L) levels. Irrigation had no impact on YAN concentrations. Treatment influences on vine vegetative growth, yield, and grape and wine composition were marginal, inconsistent, and largely influenced by climatic conditions. Cool-climate grapegrowers would benefit from applying more N in the vineyard around veraison to improve YAN without stimulating vigor or reducing the quality of grape and wine chemical composition. Increasing irrigation rates may be advantageous in seasons with high crop load; however, current commercial irrigation rates are considered adequate.

Low impact sampling of speleothems – reconciling scientific study with cave conservation

Speleothems are increasingly valued as important paleoclimate archives and yet the removal of samples from caves can come at a cost to natural heritage, impacting delicate environments with limited mechanisms for repair. Conservation of cave environments is a key responsibility for scientists and, with this in mind, we are working to develop and implement techniques that allow us to extract valuable scientific data, with minimal impact. In this study, we demonstrate the utility of low-impact reconnaissance dating surveys on caves in southern Tasmania and southwest Western Australia as a precursor to the removal of stalagmites for paleoclimate reconstruction. Small flakes of calcite were discretely extracted from the base and tip of fallen stalagmites and dated using U-Th techniques. We specifically targeted stalagmites that have naturally fallen or been previously broken by human interference, to further reduce our impact on the caves. This approach provides maximum and minimum age constraints for each stalagmite and valuable information of growth frequencies without the need to remove whole samples from the cave. Selecting the most appropriate samples to analyze based on reconnaissance ages greatly reduces the quantity of speleothem material to be removed from a cave to locate a desired interval of past time, mitigating the impacts of the research. Moreover, the reconnaissance age data enable us to build an archive of speleothem ages from the cave for future scientific research and to provide information on the age and nature of cave development, useful for cave management purposes and other studies. To assess the accuracy of this method we compared the reconnaissance age with the results of a detailed age evaluation on a small number of stalagmites removed from the caves. We have found this method to be effective and has allowed us to successfully identify several stalagmites suitable for our scientific objectives.

1325Longitudinal epidemiology of MS in the Greater Hobart region, 1961 to 2019

Abstract Background The Greater Hobart region (42.3°S) of Tasmania has the highest frequencies of MS in Australia, this consistent across studies conducted over the last half century. However, the degree of excess compared to mainland sites like Newcastle (32.5°S) has declined over time. Methods Cases were recruited from clinic-based samples and other multiple other data sources. Prevalence date was 1 June 2019. 2019 prevalence and 2009-19 incidence and mortality rates were estimated. Prevalence and incidence and mortality rates were age/sex-standardised to the 1961 and 1954 Hobart populations, respectively, to allow longitudinal comparisons. Female:male prevalence and incidence sex-ratios were also assessed. Differences between timepoints were assessed using Poisson regression. Results 472 MS cases (female:71.4%) resident on prevalence day were identified, a crude prevalence=212.3/100,000 (155.8 age/sex-standardised), 57% increase vs 2009 and 388.0% vs 1961. The 2009-19 incidence rate=7.56/100,000 person-years (7.03 age/sex-standardised), 91% increase vs 2001-9 and 218.1% vs 1951-61. The 2009-19 mortality rate was 2.25/100,000 person-years (1.12 age/sex-standardised), comparable to 2001-9 (1.00). The age/sex-standardised prevalence-sex-ratio was 2.61, comparable to 2009 (2.65), but the incidence-sex-ratio was 2.68, 31% increase vs 2001-9 (2.05). Conclusions Prevalence and incidence continue to be high in Hobart, although the differences compared to lower-latitude Newcastle have attenuated significantly. Changes in lifestyle may underlie the deterioration of the latitudinal gradient of MS in Australia. Further investigation is required to define the factors that drive these associations. Key messages MS prevalence and incidence are still highest in Australia in southern Tasmania but the latitudinal variation is declining.

Incidence of idiopathic intracranial hypertension in Southern Tasmania, Australia

IntroductionAnecdotally, the incidence of idiopathic intracranial hypertension (IIH) is increasing, linked to an increase in the obesity rate in Australian society. However, formal incidence and prevalence studies are rare. We...