The effect of intraperitoneal ropivacaine on post-operative pain and recovery after diagnostic laparoscopy and hysteroscopy: A randomised double-blind placebo-controlled trial.

BACKGROUND: Intraperitoneal local anaesthetic has shown benefit in operative laparoscopy; however, no randomised controlled trial has been reported with patients having diagnostic laparoscopy. AIMS: To determine the effect of intraperitoneal ropivacaine on post-operative analgesic requirements, pain, nausea scores and recovery following gynaecological diagnostic laparoscopy and hysteroscopy. MATERIALS AND METHODS: Randomised double-blind placebo-controlled trial. Well women aged 18-50 years, undergoing day case hysteroscopy and diagnostic laparoscopy for gynaecological indications were randomised to 20 mL of 150 mg intraperitoneal ropivacaine diluted in saline, or 20 mL normal saline instillation (placebo) at the end of the procedure. Women were followed up until eight hours post-discharge. RESULTS: Slower than anticipated recruitment meant that the study was finished before the sample size of 100 patients was achieved. Fifty-nine patients were included for analysis. Thirty-one patients were randomised to ropivacaine and 28 patients to control. Sixty-one percent of patients in both arms required opioid medication in recovery. The total median equivalent morphine dose was significantly higher in the patients randomised to control (11.7 mg) vs ropivacaine (6.7 mg), P = 0.03. Time to discharge was 20 min faster in patients randomised to ropivacaine, but this finding did not reach significance. Overall pain and nausea scores in the first eight hours showed no significant differences. CONCLUSION: There was significantly reduced opioid use in recovery when using intraperitoneal ropivacaine compared to placebo, in this randomised placebo-controlled trial on women undergoing day case diagnostic laparoscopy and hysteroscopy.

Prevalence and risk factors of ischaemic stroke in the young: a regional Australian perspective.

BACKGROUND: There is no universally accepted age cut-off for defining young strokes. AIMS: We aimed to determine, based on the profile of young stroke patients in our regional centre, an appropriate age cut-off for young strokes. METHODS: A retrospective analysis of all ischaemic stroke patients admitted to our centre from 2015 to 2017. We identified 391 ischaemic stroke patients; 30 patients between the ages of ≤50, 40 between 51-60 inclusive and 321 ≥ 61 years of age. We collected data on demographic profiles, risk factors and stroke classification using the Trial of Org 10 172 in Acute Stroke Treatment criteria. RESULTS: We found significant differences between the ≤50 and ≥61 age groups for most of the risk factors and similarities between the 51-60 inclusive and ≥ 61 age groups. At least one of the six risk factors assessed in the study was present in 86.7% of the youngest group, 97.5% of the intermediate age group and 97.2% in the oldest group. In terms of the mechanisms of stroke, the youngest and oldest age groups in our study differed in the prevalence of cryptogenic, cardioembolic and other causes of stroke. The middle and older age groups had similar mechanisms of stroke. CONCLUSIONS: The prevalence of vascular risk factors and mechanisms of stroke likewise differed significantly across age groups. This study suggests that 50 years is an appropriate age cut-off for defining young strokes and reinforces the importance of primary prevention in all age groups.

In vitro assessment of arsenic mobility in historical mine waste dust using simulated lung fluid.

Exposure studies have linked arsenic (As) ingestion with disease in mining-affected populations; however, inhalation of mine waste dust as a pathway for pulmonary toxicity and systemic absorption has received limited attention. A biologically relevant extractant was used to assess the 24-h lung bioaccessibility of As in dust isolated from four distinct types of historical gold mine wastes common to regional Victoria, Australia. Mine waste particles less than 20 µm in size (PM20) were incubated in a simulated lung fluid containing a major surface-active component found in mammalian lungs, dipalmitoylphosphatidylcholine. The supernatants were extracted, and their As contents measured after 1, 2, 4, 8 and 24 h. The resultant As solubility profiles show rapid dissolution followed by a more modest increasing trend, with between 75 and 82% of the total 24-h bioaccessible As released within the first 8 h. These profiles are consistent with the solubility profile of scorodite, a secondary As-bearing phase detected by X-ray diffraction in one of the investigated waste materials. Compared with similar studies, the cumulative As concentrations released at the 24-h time point were extremely low (range 297 ± 6-3983 ± 396 µg L-1), representing between 0.020 ± 0.002 and 0.036 ± 0.003% of the total As in the PM20.

Trace metal content in inhalable particulate matter (PM2.5-10 and PM2.5) collected from historical mine waste deposits using a laboratory-based approach.

Mine wastes and tailings are considered hazardous to human health because of their potential to generate large quantities of highly toxic emissions of particulate matter (PM). Human exposure to As and other trace metals in PM may occur via inhalation of airborne particulates or through ingestion of contaminated dust. This study describes a laboratory-based method for extracting PM2.5-10 (coarse) and PM2.5 (fine) particles from As-rich mine waste samples collected from an historical gold mining region in regional, Victoria, Australia. We also report on the trace metal and metalloid content of the coarse and fine fraction, with an emphasis on As as an element of potential concern. Laser diffraction analysis showed that the proportions of coarse and fine particles in the bulk samples ranged between 3.4-26.6 and 0.6-7.6 %, respectively. Arsenic concentrations were greater in the fine fraction (1680-26,100 mg kg-1) compared with the coarse fraction (1210-22,000 mg kg-1), and Co, Fe, Mn, Ni, Sb and Zn were found to be present in the fine fraction at levels around twice those occurring in the coarse. These results are of particular concern given that fine particles can accumulate in the human respiratory system. Our study demonstrates that mine wastes may be an important source of metal-enriched PM for mining communities.

Size-dependent characterisation of historical gold mine wastes to examine human pathways of exposure to arsenic and other potentially toxic elements.

Abandoned historical gold mining wastes often exist as geographically extensive, unremediated, and poorly contained deposits that contain elevated levels of As and other potentially toxic elements (PTEs). One of the key variables governing human exposure to PTEs in mine waste is particle size. By applying a size-resolved approach to mine waste characterisation, this study reports on the proportions of mine waste relevant to human exposure and mobility, as well as their corresponding PTE concentrations, in four distinct historical mine wastes from the gold province in Central Victoria, Australia. To the best of our knowledge, such a detailed investigation and comparison of historical mining wastes has not been conducted in this mining-affected region. Mass distribution analysis revealed notable proportions of waste material in the readily ingestible size fraction (≤250 µm; 36.1-75.6 %) and the dust size fraction (≤100 µm; 5.9-45.6 %), suggesting a high potential for human exposure and dust mobilisation. Common to all mine waste types were statistically significant inverse trends between particle size and levels of As and Zn. Enrichment of As in the finest investigated size fraction (≤53 µm) is of particular concern as these particles are highly susceptible to long-distance atmospheric transport. Human populations that reside in the prevailing wind direction from a mine waste deposit may be at risk of As exposure via inhalation and/or ingestion pathways. Enrichment of PTEs in the finer size fractions indicates that human health risk assessments based on bulk contaminant concentrations may underestimate potential exposure intensities.

The health and economic benefits of reducing intimate partner violence: an Australian example.

BACKGROUND: Intimate partner violence (IPV) has important impacts on the health of women in society. Our aim was to estimate the health and economic benefits of reducing the prevalence of IPV in the 2008 Australian female adult population. METHODS: Simulation models were developed to show the effect of a 5 percentage point absolute feasible reduction target in the prevalence of IPV from current Australian levels (27%). IPV is not measured in national surveys. Levels of psychological distress were used as a proxy for exposure to IPV since psychological conditions represent three-quarters of the disease burden from IPV. Lifetime cohort health benefits for females were estimated as fewer incident cases of violence-related disease and injury; deaths; and Disability Adjusted Life Years (DALYs). Opportunity cost savings were estimated for the health sector, paid and unpaid production and leisure from reduced incidence of IPV-related disease and deaths. Workforce production gains were estimated by comparing surveyed participation and absenteeism rates of females with moderate psychological distress (lifetime IPV exposure) against high or very high distress (current IPV exposure), and valued using the friction cost approach (FCA). The impact of improved health status on unpaid household production and leisure time were modelled from time use survey data. Potential costs associated with interventions to reduce IPV were not considered. Multivariable uncertainty analyses and univariable sensitivity analyses were undertaken. RESULTS: A 5 percentage point absolute reduction in the lifetime prevalence of IPV in the 2008 Australian female population was estimated to produce 6000 fewer incident cases of disease/injury, 74 fewer deaths, 5000 fewer DALYs lost and provide gains of 926,000 working days, 371,000 days of home-based production and 428,000 leisure days. Overall, AUD371 million in opportunity cost savings could be achievable. The greatest economic savings would be home-based production (AUD147 million), followed by leisure time (AUD98 million), workforce production (AUD94 million) and reduced health sector costs (AUD38 million). CONCLUSIONS: This study contributes new knowledge about the economic impact of IPV in females. The findings provide evidence of large potential opportunity cost savings from reducing the prevalence of IPV and reinforce the need to reduce IPV in Australia, and elsewhere.

The economic gains of achieving reduced alcohol consumption targets for Australia.

OBJECTIVES: To inform prevention policy, we estimated the economic benefits to health, production, and leisure in the 2008 Australian population of a realistic target reduction in per capita annual adult alcohol consumption. METHODS: We chose a target of 6.4 liters annually per capita on average. We modeled lifetime health benefits as fewer incident cases of alcohol-related disease, deaths, and disability adjusted life years. We estimated production gains with surveyed participation and absenteeism rates. We valued gains with friction cost and human capital methods. We estimated and valued household production and leisure gains from time-use surveys. RESULTS: A reduction of 3.4 liters of alcohol consumed annually per capita would result in one third fewer incident cases of disease (98000), deaths (380), working days lost (5 million), days of home-based production lost (54000), and a A$789-million health sector cost reduction. Workforce production had a A$427 million gain when we used the friction cost method. By contrast, we estimated a loss of 28000 leisure days and 1000 additional early retirements. CONCLUSIONS: Economic savings and health benefits from reduced alcohol consumption may be substantial-particularly in the health sector with reduced alcohol-related disease and injury.

Economic benefits of achieving realistic smoking cessation targets in Australia.

OBJECTIVES: We estimated the economic impact of reductions in the prevalence of tobacco smoking on health, production, and leisure in the 2008 Australian population. METHODS: We selected a prevalence target of 15%. Cohort lifetime health benefits were modeled as fewer incident cases of tobacco-related diseases, deaths, and disability-adjusted life-years. We estimated production gains by comparing surveyed participation and absenteeism rates of adult smokers and ex-smokers valued according to the human capital and friction cost approaches. We estimated household production and leisure gains from time use surveys and valued these gains with the appropriate proxy. RESULTS: In the 2008 Australian population, an absolute reduction in smoking prevalence of 8% would result in 158,000 fewer incident cases of disease, 5000 fewer deaths, 2.2 million fewer lost working days, and 3000 fewer early retirements and would reduce health sector costs by AUD 491 million. The gain in workforce production was AUD 415 million (friction cost) or AUD 863 million (human capital), along with gains of 373,000 days of household production and 23,000 days of leisure time. CONCLUSIONS: Lowering smoking prevalence rates can lead to substantial economic savings and health benefits.

The economic benefits of reducing physical inactivity: an Australian example.

BACKGROUND: Physical inactivity has major impacts on health and productivity. Our aim was to estimate the health and economic benefits of reducing the prevalence of physical inactivity in the 2008 Australian adult population. The economic benefits were estimated as 'opportunity cost savings', which represent resources utilized in the treatment of preventable disease that are potentially available for re-direction to another purpose from fewer incident cases of disease occurring in communities. METHODS: Simulation models were developed to show the effect of a 10% feasible, reduction target for physical inactivity from current Australian levels (70%). Lifetime cohort health benefits were estimated as fewer incident cases of inactivity-related diseases; deaths; and Disability Adjusted Life Years (DALYs) by age and sex. Opportunity costs were estimated as health sector cost impacts, as well as paid and unpaid production gains and leisure impacts from fewer disease events associated with reduced physical inactivity. Workforce production gains were estimated by comparing surveyed participation and absenteeism rates of physically active and inactive adults, and valued using the friction cost approach. The impact of an improvement in health status on unpaid household production and leisure time were modeled from time use survey data, as applied to the exposed and non-exposed population subgroups and valued by suitable proxy. Potential costs associated with interventions to increase physical activity were not included. Multivariable uncertainty analyses and univariate sensitivity analyses were undertaken to provide information on the strength of the conclusions. RESULTS: A 10% reduction in physical inactivity would result in 6,000 fewer incident cases of disease, 2,000 fewer deaths, 25,000 fewer DALYs and provide gains in working days (114,000), days of home-based production (180,000) while conferring a AUD96 million reduction in health sector costs. Lifetime potential opportunity cost savings in workforce production (AUD12 million), home-based production (AUD71 million) and leisure-based production (AUD79 million) was estimated (total AUD162 million 95% uncertainty interval AUD136 million, AUD196 million). CONCLUSIONS: Opportunity cost savings and health benefits conservatively estimated from a reduction in population-level physical inactivity may be substantial. The largest savings will benefit individuals in the form of unpaid production and leisure gains, followed by the health sector, business and government.

The societal benefits of reducing six behavioural risk factors: an economic modelling study from Australia.

BACKGROUND: A large proportion of disease burden is attributed to behavioural risk factors. However, funding for public health programs in Australia remains limited. Government and non-government organisations are interested in the productivity effects on society from reducing chronic diseases. We aimed to estimate the potential health status and economic benefits to society following a feasible reduction in the prevalence of six behavioural risk factors: tobacco smoking; inadequate fruit and vegetable consumption; high risk alcohol consumption; high body mass index; physical inactivity; and intimate partner violence. METHODS: Simulation models were developed for the 2008 Australian population. A realistic reduction in current risk factor prevalence using best available evidence with expert consensus was determined. Avoidable disease, deaths, Disability Adjusted Life Years (DALYs) and health sector costs were estimated. Productivity gains included workforce (friction cost method), household production and leisure time. Multivariable uncertainty analyses and correction for the joint effects of risk factors on health status were undertaken. Consistent methods and data sources were used. RESULTS: Over the lifetime of the 2008 Australian adult population, total opportunity cost savings of AUD2,334 million (95% Uncertainty Interval AUD1,395 to AUD3,347; 64% in the health sector) were found if feasible reductions in the risk factors were achieved. There would be 95,000 fewer DALYs (a reduction of about 3.6% in total DALYs for Australia); 161,000 less new cases of disease; 6,000 fewer deaths; a reduction of 5 million days in workforce absenteeism; and 529,000 increased days of leisure time. CONCLUSIONS: Reductions in common behavioural risk factors may provide substantial benefits to society. For example, the total potential annual cost savings in the health sector represent approximately 2% of total annual health expenditure in Australia. Our findings contribute important new knowledge about productivity effects, including the potential for increased household and leisure activities, associated with chronic disease prevention. The selection of targets for risk factor prevalence reduction is an important policy decision and a useful approach for future analyses. Similar approaches could be applied in other countries if the data are available.

Asymptomatic Carotid Stenosis Is Associated With Circadian and Other Variability in Embolus Detection.

Background and Purpose: Variability in transcranial Doppler (TCD) detection of embolic signals (ES) is important for risk stratification. We tested the effect of time of day on ES associated with 60-99% asymptomatic carotid stenosis. Materials and Methods: Subjects were from the Asymptomatic Carotid Stenosis Embolus Detection (ASED) Study such that half were previously ES-positive and half ES-negative with 6-monthly 60-min TCD monitoring. All underwent bilateral TCD monitoring for two 12-h sessions separated by 24 h. ES detection rates were calculated using 6 and 4-h intervals from midnight and effective TCD monitoring time. Results: Ten subjects (8 male, mean age 79.5 years) were monitored. Over 24 h, 5/10 study arteries with 60-99% asymptomatic carotid stenosis were ES-positive (range 1-28 ES/artery, 56 total ES from 177.9 total effective monitoring hours). The remaining five study arteries and all eight successfully monitored contralateral arteries were ES-negative. Using 6-h intervals the mean ES detection rate peaked at 0600-midday (0.64/h) and was lowest 1800-midnight (0.09/h) with an incidence rate ratio of 7.26 (95% CI 2.52-28.64, P ≤ 0.001). Using 4-h intervals the mean ES detection rate peaked at 0800-midday (0.64/h) and was lowest midnight-0400 (0.12/h) with an incidence rate ratio of 5.51 (95% CI 1.78-22.67, P = 0.001). Conclusions: Embolism associated with asymptomatic carotid stenosis shows circadian variation with highest rates 4-6 h before midday. This corresponds with peak circadian incidence of stroke and other vascular complications. These and ASED Study results show that monitoring frequency, duration, and time of day are important in ES detection.

Estimating the prevalence of sleep-disordered breathing in community-based, long-term stroke survivors using a validated predictive model.

BACKGROUND: Assessing sleep-disordered breathing (SDB) in aged or disabled populations is difficult. AIMS: To validate a multivariable apnea risk prediction index (MAPI) in stroke survivors and estimate SDB prevalence (apnea-hypopnea index >or=10) in a community-based stroke cohort. METHODS: Self-reported sleep apnea symptoms, demographic and anthropometric data were obtained from a hospital-based (SCOPES II, n = 152) and a community-based (NEMESIS, n = 431) cohort at about 3 years after stroke. Logistic regression models for prediction of SDB using the MAPI were validated with home-based nocturnal polygraphic data recordings obtained in 74 SCOPES II participants. RESULTS: NEMESIS subjects (median age 76, females 45%) were older than SCOPES II subjects (median age 70, females 42%). SDB prevalence was 44.9% in the nocturnal polygraphy subset, and estimated as 44.1% (SCOPES II) and 50.6% (NEMESIS) using a modified MAPI. CONCLUSION: The MAPI can be reliably used in stroke cohorts and SDB affects about half of chronic stroke survivors.

Economic evaluation of Australian stroke services: a prospective, multicenter study comparing dedicated stroke units with other care modalities.

BACKGROUND AND PURPOSE: Level I evidence from randomized controlled trials demonstrates that the model of hospital care influences stroke outcomes; however, the economic evaluation of such is limited. An economic appraisal of 3 acute stroke care models was facilitated through the Stroke Care Outcomes: Providing Effective Services (SCOPES) study in Melbourne, Australia. The aim was to describe resource use up to 28 weeks poststroke for each model and examine the cost-effectiveness of stroke care units (SCUs). METHODS: A prospective, multicenter, cohort study design was used. Costs and outcomes of stroke patients receiving 100% treatment in 1 of 3 inpatient care models (SCUs, mobile service, conventional care) were compared. Health-sector resource use up to 28 weeks was measured in 1999. Outcomes were thorough adherence to a suite of important clinical processes and the number of severe inpatient complications. RESULTS: The sample comprised 395 participants (mean age 73 [SD 14], 77% first-ever strokes, males 53%). When compared with conventional care (n=84), costs for mobile service (n=209) were significantly higher (P=0.024), but borderline for SCU (n=102, P=0.08; 12,251 Australian dollars; 15,903 Australian dollars; 15,383 Australian dollars respectively). This was primarily explained by the greater use of specialist medical services. The incremental cost-effectiveness of SCUs over conventional care was 9867 Australian dollars per patient achieving thorough adherence to clinical processes and 16,372 Australian dollars per patient with severe complications avoided, based on costs to 28 weeks. CONCLUSIONS: Although acute SCU costs are generally higher, they are more cost-effective than either mobile service or conventional care.

Sleep disordered breathing in chronic stroke survivors. A study of the long term follow-up of the SCOPES cohort using home based polysomnography.

Prevalence of sleep-disordered breathing (SDB) (apnea-hypopnea index [AHI] > or = 5) in acute stroke patients ranges between 44% and 95%, compared to the community prevalence, 9 to 35% for women and 8 to 57% for men [age range 30-60 years]. Limited data exists beyond 3 months following stroke. We assessed the prevalence of SDB amongst stroke survivors at 3 years and compared results to data reported in normal and elderly populations. 90/143 eligible stroke survivors from an existing cohort underwent a home based sleep study. Mean age of the 78 subjects with a valid sleep study was 64 years (SD 15). Prevalence of SDB (AHI > or = 5) was 81% (95% CI 72% to 90%) and sleep apnoea syndrome (AHI > or = 5 plus ESS score > or =11) was 20% (95% CI 11% to 29%). Important predictors for AHI > or = 15 were haemorrhagic stroke (aOR12.06 [1.42-102.74]) and stroke severity at 1 month (aOR4.15 [1.05-16.38]). Large case-control studies are needed.

Multicenter comparison of processes of care between Stroke Units and conventional care wards in Australia.

BACKGROUND AND PURPOSE: Approximately 23% of Australian hospitals provide Stroke Units (SUs). Evidence suggests that clinical outcomes are better in SUs than with conventional care. Reasons may include greater adherence to processes of care (PoC). The primary hypothesis was that adherence to selected PoC is greater in SUs than in other acute care models. METHODS: Prospective, multicenter, single-blinded design. Models of care investigated: SUs, mobile services, and conventional care. Selected PoC were related to care models and participant outcomes. Data were collected at acute hospitalization (median 9 days) and at medians of 8 and 28 weeks after stroke. RESULTS: 1701 patients were screened from 8 hospitals, 823 were eligible, and 468 participated. Response rate was 96% at final follow-up. Mean age was 73 years (SD 14). Overall PoC adherence rates for individual care models were SU 75%, mobile service 65%, and conventional care 52% (P<0.001). The adjusted odds of participants being alive at discharge if adhering to all or all but 1 PoC was significant (aOR 3.63; 95% CI: 1.04 to 12.66; P=0.043). Important trends at 28 weeks were found for being at home (aOR 3.09; 95% CI: 0.96 to 9.87; P=0.058) and independent (aOR 2.61; 95% CI: 0.96 to 7.10; P=0.061), with complete PoC adherence. CONCLUSIONS: Adherence to key PoC was higher in SUs than in other models. For all patients, adherence to PoC was associated with improved mortality at discharge and trends found with independence at home, providing support for the need to increase access to stroke units.

Cancer incidence and soil arsenic exposure in a historical gold mining area in Victoria, Australia: a geospatial analysis.

Soil and mine waste around historical gold mining sites may have elevated arsenic concentrations. Recent evidence suggests some systemic arsenic absorption by residents in the goldfields region of Victoria, Australia. Victorian Cancer Registry and geochemical data were accessed for an ecological geographical correlation study, 1984-2003. Spatial empirical Bayes smoothing was applied when estimating standardised incidence ratios (SIRs) for cancers in 61 statistical local areas. The derived soil arsenic exposure metric ranged from 1.4 to 1857 mg/kg. Spatial autoregressive modelling detected increases in smoothed SIRs for all cancers of 0.05 (95% confidence interval (CI), 0.02-0.08) and 0.04 (0.01-0.07) per 2.7-fold increase in the natural log-transformed exposure metric for males and females, respectively, in more socioeconomically disadvantaged areas; for melanoma in males (0.05 (0.01-0.08) adjusted for disadvantage) and females (0.05 (0.02-0.09) in disadvantaged areas). Excess risks were estimated for all cancers (relative risk 1.21 (95% CI, 1.15-1.27) and 1.08 (1.03-1.14)), and melanoma (1.52 (1.25-1.85) and 1.29 (1.08-1.55)), for males and females, respectively, in disadvantaged areas in the highest quintile of the exposure metric relative to the lowest. Our findings suggest small but significant increases in past cancer risk associated with increasing soil arsenic in socioeconomically disadvantaged areas and demonstrate the robustness of this geospatial approach.

Understanding mortality in the 1918-1919 influenza pandemic in England and Wales.

BACKGROUND: The causes of recurrent waves in the 1918-1919 influenza pandemic are not fully understood. OBJECTIVES: To identify the risk factors for influenza onset, spread and mortality in waves 1, 2 and 3 (summer, autumn and winter) in England and Wales in 1918-1919. METHODS: Influenza mortality rates for 333 population units and putative risk factors were analysed by correlation and by regressions weighted by population size and adjusted for spatial trends. RESULTS: For waves 1 and 3, influenza mortality was higher in younger, northerly and socially disadvantaged populations experiencing higher all-cause mortality in 1911-1914. Influenza mortality was greatest in wave 2, but less dependent on underlying population characteristics. Wave duration was shorter in areas with higher influenza mortality, typically associated with increasing population density. Regression analyses confirmed the importance of geographical factors and pre-pandemic mortality for all three waves. Age effects were complex, with the suggestion that younger populations with greater mortality in wave 1 had lesser mortality in wave 2. CONCLUSIONS: Our findings suggest that socially disadvantaged populations were more vulnerable, that older populations were partially protected by prior immunity in wave 1 and that exposure of (younger) populations in one wave could protect against mortality in the subsequent wave. An increase in viral virulence could explain the greater mortality in wave 2. Further modelling of causal processes will help to explain, in considerable detail, how social and geographical factors, season, pre-existing and acquired immunity and virulence affected viral transmission and pandemic mortality in 1918-1919.

Arsenic microdistribution and speciation in toenail clippings of children living in a historic gold mining area.

Arsenic is naturally associated with gold mineralisation and elevated in some soils and mine waste around historical gold mining activity in Victoria, Australia. To explore uptake, arsenic concentrations in children's toenail clippings and household soils were measured, and the microdistribution and speciation of arsenic in situ in toenail clipping thin sections investigated using synchrotron-based X-ray microprobe techniques. The ability to differentiate exogenous arsenic was explored by investigating surface contamination on cleaned clippings using depth profiling, and direct diffusion of arsenic into incubated clippings. Total arsenic concentrations ranged from 0.15 to 2.1 microg/g (n=29) in clipping samples and from 3.3 to 130 microg/g (n=22) in household soils, with significant correlation between transformed arsenic concentrations (Pearson's r=0.42, P=0.023) when household soil was treated as independent. In clipping thin sections (n=2), X-ray fluorescence (XRF) mapping showed discrete layering of arsenic consistent with nail structure, and irregular arsenic incorporation along the nail growth axis. Arsenic concentrations were heterogeneous at 10x10 microm microprobe spot locations investigated (<0.1 to 13.3 microg/g). X-ray absorption near-edge structure (XANES) spectra suggested the presence of two distinct arsenic species: a lower oxidation state species, possibly with mixed sulphur and methyl coordination (denoted As(approximately III)(-S, -CH3)); and a higher oxidation state species (denoted As(approximately V)(-O)). Depth profiling suggested that surface contamination was unlikely (n=4), and XRF and XANES analyses of thin sections of clippings incubated in dry or wet mine waste, or untreated, suggested direct diffusion of arsenic occurred under moist conditions. These findings suggest that arsenic in soil contributes to some systemic absorption associated with periodic exposures among children resident in areas of historic gold mining activity in Victoria, Australia. Future studies are required to ascertain if adverse health effects are associated with current levels of arsenic uptake.

Patterns of stroke recurrence according to subtype of first stroke event: the North East Melbourne Stroke Incidence Study (NEMESIS).

BACKGROUND: Specific information about the nature of recurrent events that occur after each subtype of index stroke may be useful for refining preventive therapies. We aimed to determine whether stroke recurrence rates, the pattern of subtype recurrence, and prescription of secondary prevention agents differed according to initial stroke subtype. METHODS: Multiple overlapping sources were used to recruit all first-ever stroke patients from a geographically defined region of Melbourne, Australia over a 3-year period from 1996 to 1999. Potential stroke recurrences (fatal and nonfatal) occurring within 2 years of the initial event were identified following patient interview and follow up of death records. Subjects were classified into the different Oxfordshire groups and the type of first-ever stroke was compared with recurrent stroke events. RESULTS: One thousand, three hundred and sixteen first-ever strokes were registered during the 3-year period (mean age 74.4 years). A total of 103 first recurrent stroke events (fatal and nonfatal) occurred among those with a first-ever ischemic stroke or intracerebral hemorrhage (ICH) during the 2-year follow-up period. The recurrent stroke subtype was different to the index stroke subtype in most (78%) patients. People with partial anterior circulation infarct had the greatest proportion of recurrences (13%), with a third of these being the more severe total anterior circulation infarct subgroup. The relative risk of ICH after an index lacunar infarct (LACI) compared with an index non-LACI was 4.06 (95% CI 1.10-14.97, P=0.038). Prescription of secondary prevention agents was greater at 2 years after stroke than at hospital discharge, and was similar between ischemic stroke subtypes. CONCLUSION: Approximately 9% of people with first-ever stroke suffered a recurrent event, despite many being prescribed secondary prevention agents. This has implications for the uptake of current preventive strategies and the development of new strategies. The possibility that ICH is greater among index LACI cases needs to be confirmed.

Quality of stroke care within a hospital: effects of a mobile stroke service.

OBJECTIVE: An Australian stroke services study (SCOPES) has developed a framework to compare different forms of acute stroke services, the gold standard being localised stroke units. We aimed to use this framework to assess changes in the quality of stroke care over time as a sequential audit process. DESIGN AND SETTING: A retrospective medical record audit comparing 100 sequential stroke admissions (July 2002 to June 2003) two years after institution of a mobile stroke service (MSS) with 100 historical controls (September 1998 to October 1999) at a 260-bed hospital in Melbourne. The MSS results were also compared with stroke units in SCOPES. MAIN OUTCOME MEASURES: Adherence to quality indicators and standard measures of outcome (complications, length of stay and discharge disability) after implementing the MSS. RESULTS: Significant improvements were seen in prophylaxis for deep-vein thrombosis, incontinence management, premorbid function documentation, frequent neurological observations and early occupational therapy. The MSS demonstrated fewer severe complications (9% versus 24%; P = 0.004), reduced median length of stay (discharged patients: 12.0 days versus 18.5 days; P = 0.003) and more patients were independent at discharge (32% versus 9%; P < 0.001). Comparison with SCOPES stroke units showed our MSS could improve in incontinence management and appropriate use of antiplatelet therapy. CONCLUSION: Institution of the MSS was associated with improvements in the quality of stroke care. This study demonstrates application of an audit procedure for quality improvement in hospital stroke management and the potential to improve stroke services in smaller centres.