Suicide-Related Out-of-Hospital Cardiac Arrests in Queensland, Australia: Temporal Trends of Characteristics and Outcomes over 14 Years.

BACKGROUND: Research into suicide-related out-of-hospital cardiac arrests (OHCA) using OHCA registries is scant. A more complete understanding of methods, patient characteristics, and outcomes is essential to inform prehospital management strategies and public health interventions. METHODS: Included were all OHCA attended by Queensland Ambulance Service (Australia) paramedics between 1 January 2007 and 31 December 2020, where suicide-related causes could be identified. Age- and sex-standardized incidence rates were calculated. Suicide methods, patient characteristics, and survival outcomes were described. Factors associated with survival outcomes were investigated. RESULTS: Seven thousand three hundred and fifty-six suicide-related OHCA cases were included. The incidence rates increased from 9.0 per 100,000 population in 2007 to 12.4 in 2020. The incidence rates for males were four times those for females; however, incidence rates for females have increased faster than for males. Hanging was the most common suicide method (63%). Twenty-three percent of patients received resuscitation attempts by paramedics. Among those, the rates of return of spontaneous circulation (ROSC) sustained to hospital arrival, survival to hospital discharge, and survival to 30 days were 28.6, 8.5, and 8.0%, respectively. Over time, the rates of ROSC upon hospital arrival increased, whereas the rates of survival to discharge and 30-day survival remained stable. CONCLUSION: The incidence of prehospital-identified suicide-related OHCA in Queensland has increased over time. The prognosis of suicide-related OHCA is poor. Prevention measures should focus on early identification and treatment of individuals having a high risk of suicide. Emergency medical services need to have sufficient training for telecommunicators and paramedics in suicide risk assessment and identification.

Use of psychotropic medications in adults with intellectual disability: A systematic review and meta-analysis.

OBJECTIVE: This study presents the proportion of adults with intellectual disability using psychotropic medications including antipsychotics, antidepressants, anxiolytics, hypnotics and sedatives, and psychostimulants. METHODS: A search was performed in PubMed, Embase, PsycINFO, Web of Science, and Scopus up to 31 December 2021. Articles were included if they reported the proportion of adults with intellectual disability using psychotropic medications. Frequency of use was estimated using a random effects meta-analysis. Meta-regression analysis was used to assess the association between study-level characteristics and variability in estimates, when heterogeneity was considerable. RESULTS: Twenty-four articles were included in pooled analysis. The pooled prevalence of psychotropic medications was 41% (95% confidence interval: 35-46%). Pooled prevalences of subclasses were as follows: antipsychotics 31% (27-35%), antidepressants 14% (9-19%), anxiolytics 9% (4-15%), hypnotics/sedatives 5% (2-8%), and psychostimulants 1% (1-2%). Heterogeneity was considerable between studies, except for psychostimulants. There was no significant association between assessed characteristics and variability in prevalence estimates. CONCLUSION: Two-fifths of adults with intellectual disability were prescribed psychotropic medications. Antipsychotics and antidepressants were used by one-third and one-seventh of adults, respectively. There was considerable variability between studies, and further investigation is required to determine the source of variability. More studies are needed to better characterise prescribed psychotropic medications, including effectiveness and adverse effects, to ensure appropriate use of these drugs.

Survival after Resuscitated Out-of-Hospital Cardiac Arrest in Patients with Paramedic-Identified ST-Segment Elevation Myocardial Infarction Treated with Primary Percutaneous Coronary Intervention.

Background: ST-segment elevation myocardial infarction (STEMI) is a common cause of out-of-hospital cardiac arrest (OHCA). For these patients, urgent angiography and revascularization is an important treatment goal. There is a lack of data on the prognosis of STEMI patients after OHCA, who are diagnosed and treated by paramedics prior to hospital transport for primary percutaneous coronary intervention (PCI). Methods: Included were adult STEMI patients identified and treated by paramedics in Queensland (Australia) from January 2016 to December 2019, transported to a hospital for primary PCI, and receiving primary PCI. Patients were grouped into those with resuscitated OHCA and those without OHCA. Clinically-important time intervals, angiographic and clinical profiles, and survival were described. Results: Patients with OHCA had longer time intervals from prehospital STEMI identification to reperfusion than those without OHCA (median 97 versus 87 mins, p = 0.001). The former had higher rates of cardiac arrhythmia history (50.5 versus 12.4%, p < 0.001), classified low left ventricular ejection fraction on admission (64.9 versus 50.1%, p = 0.006), and cardiogenic shock (5.2 versus 1.2%, p = 0.011) than the latter. A significantly higher proportion of patients with OHCA had multiple diseased vessels (16.9 versus 8.3%, p = 0.005). In-hospital, 30-day, and one-year mortality was low, being 4.1%, 4.1% and 5.2%, respectively, for STEMI patients with OHCA. The corresponding figures for those without OHCA were 1.6%, 1.8% and 3.3%, respectively. Conclusions: Survival in paramedic-identified STEMI patients treated with primary PCI following OHCA resuscitation was high. Rapid angiography and reperfusion are critical in these patients.

Epidemiology, management and survival outcomes of adult out-of-hospital traumatic cardiac arrest due to blunt, penetrating or burn injury.

BACKGROUND: Survival from out-of-hospital traumatic cardiac arrest (TCA) is poor. Regional variation exists regarding epidemiology, management and outcomes. Data on prognostic factors are scant. A better understanding of injury patterns and outcome determinants is key to identifying opportunities for survival improvement. METHODS: Included were adult (≥18 years) out-of-hospital TCA due to blunt, penetrating or burn injury, who were attended by Queensland Ambulance Service paramedics between 1 January 2007 and 31 December 2019. We compared the characteristics of patients who were pronounced dead on paramedic arrival and those receiving resuscitation from paramedics. Intra-arrest procedures were described for attempted-resuscitation patients. Survival up to 6 months postarrest was reported, and factors associated with survival were investigated. RESULTS: 3891 patients were included; 2394 (61.5%) were pronounced dead on paramedic arrival and 1497 (38.5%) received resuscitation from paramedics. Most arrests (79.8%) resulted from blunt trauma. Motor vehicle collision (42.4%) and gunshot wound (17.7%) were the most common injury mechanisms in patients pronounced dead on paramedic arrival, whereas the most prevalent mechanisms in attempted-resuscitation patients were motor vehicle (31.3%) and motorcycle (20.6%) collisions. Among attempted-resuscitation patients, rates of transport and survival to hospital handover, to hospital discharge and to 6 months were 31.9%, 15.3%, 9.8% and 9.8%, respectively. Multivariable model showed that advanced airway management (adjusted OR 1.84; 95% CI 1.06 to 3.17), intravenous access (OR 5.04; 95% CI 2.43 to 10.45) and attendance of high acuity response unit (highly trained prehospital care clinicians) (OR 2.54; 95% CI 1.25 to 5.18) were associated with improved odds of survival to hospital handover. CONCLUSIONS: By including all paramedic-attended patients, this study provides a more complete understanding of the epidemiology of out-of-hospital TCA. Contemporary survival rates from adult out-of-hospital TCA who receive resuscitation from paramedics may be higher than historically thought. Factors identified in this study as associated with survival may be useful to guide prognostication and treatment.

Characteristics associated with frequent health system use by Australian adults with intellectual disability: A cohort study.

BACKGROUND: In a cohort of adults with intellectual disability who were followed for up to 16-years, we investigated characteristics associated with frequent emergency department (ED) presentations, hospitalisation, and psychiatric care. METHOD: Community-dwelling adults with intellectual disability residing in Queensland, Australia, were followed from 1999 to 2015. Healthcare presentations were extracted from administrative databases. Adults who presented frequently were identified and characteristics associated with frequent presentations were identified. RESULTS: Data from 445 adults were analysed. Chronic disease and challenging behaviour were associated with frequent ED presentations (adjusted odds ratio = 1.8, 95% confidence interval = 1.1-3.0 and aOR = 2.2, 95% CI = 1.2-3.9 respectively). Chronic disease and severe/profound intellectual disability were associated with frequent hospitalisations (aOR = 1.9, 95% CI = 1.2-3.2 and aOR = 2.0, 95% CI = 1.2-3.3 respectively). Psychotropic medication use was associated with frequent psychiatric presentations (aOR = 1.9, 95% CI = 1.0-3.4). CONCLUSIONS: Adults at high risk of frequent healthcare presentations should be identified for programmes of optimising health system use, and potentially improving health care quality.

Ambient temperatures, heatwaves and out-of-hospital cardiac arrest in Brisbane, Australia.

BACKGROUND: The health impacts of temperatures are gaining attention in Australia and worldwide. While a number of studies have investigated the association of temperatures with the risk of cardiovascular diseases, few examined out-of-hospital cardiac arrest (OHCA) and none have done so in Australia. This study examined the exposure-response relationship between temperatures, including heatwaves and OHCA in Brisbane, Australia. METHODS: A quasi-Poisson regression model coupled with a distributed lag non-linear model was employed, using OHCA and meteorological data between 1 January 2007 and 31 December 2019. Reference temperature was chosen to be the temperature of minimum risk (21.4°C). Heatwaves were defined as daily average temperatures at or above a heat threshold (90th, 95th, 98th, 99th percentile of the yearly temperature distribution) for at least two consecutive days. RESULTS: The effect of any temperature above the reference temperature was not statistically significant; whereas low temperatures (below reference temperature) increased OHCA risk. The effect of low temperatures was delayed for 1 day, sustained up to 3 days, peaking at 2 days following exposures. Heatwaves significantly increased OHCA risk across the operational definitions. When a threshold of 95th percentile of yearly temperature distribution was used to define heatwaves, OHCA risk increased 1.25 (95% CI 1.04 to 1.50) times. When the heat threshold for defining heatwaves increased to 99th percentile, the relative risk increased to 1.48 (1.11 to 1.96). CONCLUSIONS: Low temperatures and defined heatwaves increase OHCA risk. The findings of this study have important public health implications for mitigating strategies aimed at minimising temperature-related OHCA.

Survival in Patients with Paramedic-Identified ST-Segment Elevation Myocardial Infarction.

BACKGROUND: Field identification and treatment of ST-segment elevation myocardial infarction (STEMI) by paramedics is an important component of care for these patients. There is a paucity of studies in the setting of paramedic-identified STEMI. This study investigated mortality and factors associated with mortality in a large state-wide prehospital STEMI sample. Methods: Included were adult STEMI patients identified and treated with reperfusion therapy by paramedics in the field between January 2016 and December 2018 in Queensland, Australia. 30-day and one-year all-cause mortality was compared between two prehospital reperfusion pathways: prehospital fibrinolysis versus direct referral to a hospital for primary percutaneous coronary intervention (direct percutaneous coronary intervention [PCI] referral). For prehospital fibrinolysis patients, factors associated with failed fibrinolysis were investigated. For direct PCI referral patients, factors associated with mortality were examined. Results: The 30-day mortality was 2.2% for prehospital fibrinolysis group and 1.8% for direct PCI referral group (p = 0.661). One-year mortality for the two groups was 2.7% and 3.2%, respectively (p = 0.732). Failed prehospital fibrinolysis was observed in 20.1% of patients receiving this therapy, with male gender and history of heart failure being predictors. For direct PCI referral group, low left ventricular ejection fraction (LVEF) on admission and cardiogenic shock prior to PCI were predictors of both 30-day and one-year mortality. Aboriginal and Torres Strait Islander status, and impaired kidney function on admission, were associated with one-year but not 30-day mortality. Being overweight was associated with lower 30-day mortality. Conclusions: Mortality in STEMI patients identified and treated by paramedics was low, and the prehospital fibrinolysis treatment pathway was effective with a mortality rate comparable to that of patients undergoing primary PCI. Key words: prehospital; Queensland; cardiac reperfusion; STEMI.

Prehospital ST-Segment Elevation Myocardial Infarction (STEMI) in Queensland, Australia: Findings from 11 Years of the Statewide Prehospital Reperfusion Strategy.

Background: Field identification and treatment of ST-segment elevation myocardial infarction (STEMI) by paramedics is an important component of the continuum of care for these patients. This study described real-world clinical practice in prehospital management of STEMI patients in Queensland, Australia. Methods: Retrospective analysis of data sourced from the STEMI database of the Queensland Ambulance Service, Australia. Adult STEMI patients identified by paramedics between February 2008 and December 2018 in Queensland were included. Key aspects of prehospital STEMI care were described. Clinically-important time intervals from symptom onset to reperfusion were reported. Results: A total of 8,388 patients were included. The proportion of patients receiving prehospital reperfusion treatment has improved markedly, increasing from 34% in 2008 to 65% in 2018 (p < 0.001). Direct referral of patients to a hospital for primary percutaneous coronary intervention (pPCI), and administration of preparatory antiplatelet and anticoagulant medications, was the main reperfusion treatment pathway, accounting for 75% of patients receiving reperfusion treatment. Time from paramedic arrival at scene to first 12-lead electrocardiogram has significantly reduced, from 11 minutes in 2008 to 6 minutes from 2012 onwards (p < 0.001). Median (interquartile range, IQR) time from prehospital STEMI identification to reperfusion was 88 (74-103) minutes for patients referred by paramedics to a hospital for pPCI. Fifty-five percent of patients who underwent pPCI achieved time from STEMI identification to reperfusion within 90 minutes. For patients receiving prehospital fibrinolysis, median (IQR) time from STEMI identification to administration of a fibrinolytic agent was 21 (12-33) minutes. Conclusion: The implementation of a statewide prehospital reperfusion strategy has markedly improved the rate of prehospital reperfusion treatment and key time metrics. Ongoing quality improvement efforts are required to further reduce delays in reperfusion.

Cost-effectiveness of 3 months of weekly rifapentine and isoniazid compared with other standard treatment regimens for latent tuberculosis infection: a decision analysis study.

Background: Latent tuberculosis infection (LTBI) is a critical driver of the global burden of active TB, and therefore LTBI treatment is key for TB elimination. Treatment regimens for LTBI include self-administered daily isoniazid for 6 (6H) or 9 (9H) months, self-administered daily rifampicin plus isoniazid for 3 months (3RH), self-administered daily rifampicin for 4 months (4R) and weekly rifapentine plus isoniazid for 3 months self-administered (3HP-SAT) or administered by a healthcare worker as directly observed therapy (3HP-DOT). Data on the relative cost-effectiveness of these regimens are needed to assist policymakers and clinicians in selecting an LTBI regimen. Objectives: To evaluate the cost-effectiveness of all regimens for treating LTBI. Methods: We developed a Markov model to investigate the cost-effectiveness of 3HP-DOT, 3HP-SAT, 4R, 3RH, 9H and 6H for LTBI treatment in a cohort of 10000 adults with LTBI. Cost-effectiveness was evaluated from a health system perspective over a 20 year time horizon. Results: Compared with no preventive treatment, 3HP-DOT, 3HP-SAT, 4R, 3RH, 9H and 6H prevented 496, 470, 442, 418, 370 and 276 additional cases of active TB per 10000 patients, respectively. All regimens reduced costs and increased QALYs compared with no preventive treatment. 3HP was more cost-effective under DOT than under SAT at a cost of US$27948 per QALY gained. Conclusions: Three months of weekly rifapentine plus isoniazid is more cost-effective than other regimens. Greater recognition of the benefits of short-course regimens can contribute to the scale-up of prevention and achieving the 'End TB' targets.

Predicting the Outcomes of New Short-Course Regimens for Multidrug-Resistant Tuberculosis Using Intrahost and Pharmacokinetic-Pharmacodynamic Modeling.

Short-course regimens for multidrug-resistant tuberculosis (MDR-TB) are urgently needed. Limited data suggest that the new drug bedaquiline (BDQ) may have the potential to shorten MDR-TB treatment to less than 6 months when used in conjunction with standard anti-TB drugs. However, the feasibility of BDQ in shortening MDR-TB treatment duration remains to be established. Mathematical modeling provides a platform to investigate different treatment regimens and predict their efficacy. We developed a mathematical model to capture the immune response to TB inside a human host environment. This model was then combined with a pharmacokinetic-pharmacodynamic model to simulate various short-course BDQ-containing regimens. Our modeling suggests that BDQ could reduce MDR-TB treatment duration to just 18 weeks (4 months) while still maintaining a very high treatment success rate (100% for daily BDQ for 2 weeks, or 95% for daily BDQ for 1 week during the intensive phase). The estimated time to bacterial clearance of these regimens ranges from 27 to 33 days. Our findings provide the justification for empirical evaluation of short-course BDQ-containing regimens. If short-course BDQ-containing regimens are found to improve outcomes, then we anticipate clear cost savings and a subsequent improvement in the efficiency of national TB programs.

Primary antifungal prophylaxis in adult patients with acute lymphoblastic leukaemia: a multicentre audit.

OBJECTIVES: The primary objectives were to investigate the prescribing practices of primary antifungal prophylaxis (PAP) and incidence of invasive fungal disease (IFD) in adult patients with ALL receiving induction-consolidation chemotherapy. Secondary objectives were to determine risk factors for IFD and resource utilization associated with IFD. METHODS: A retrospective chart review of adult patients with ALL from commencement of induction until completion of consolidation chemotherapy was undertaken from January 2008 to June 2013 in four hospitals in Melbourne, Australia. IFD was classified according to the revised European Organisation for Research and Treatment of Cancer criteria. Cost analysis was performed from an Australian public hospital perspective. RESULTS: Ninety-eight patients were included in the audit; 83 (85%) received PAP. Most patients (49/83, 59%) switched between two different antifungal agents, predominantly between liposomal amphotericin B and an azole. Five proven/probable and six possible IFD cases were identified. Proven/probable IFD was most common in patients receiving the BFM95 chemotherapy protocol. The incidence of proven/probable IFD was significantly lower in patients receiving PAP compared with those who did not (2/78, 2.6% versus 3/14, 21.4%; P = 0.024). For every five patients receiving PAP, one proven/probable IFD case would be prevented. Proven/probable IFD was associated with an additional median cost of 121,520 Australian dollars (95% CI: 90,781-180,141 Australian dollars; P < 0.001) compared with patients without IFD. CONCLUSIONS: This is the first multicentre study evaluating PAP use in patients with ALL. With the caveats of interpretation of retrospective, non-randomized data, PAP was associated with a reduced IFD risk.

Cost-effectiveness analysis of an ambulance service-operated specialised cardiac vehicle with mobile extracorporeal cardiopulmonary resuscitation capacity for out-of-hospital cardiac arrests in Queensland, Australia.

OBJECTIVE: Extracorporeal CPR (E-CPR) has been primarily limited to the in-hospital setting. A few systems around the world have implemented pre-hospital mobile E-CPR in the form of a dedicated cardiac vehicle fitted with specialised equipment and clinicians required for the performance of E-CPR on-scene. However, evidence of the outcomes and cost-effectiveness of mobile E-CPR remain to be established. We evaluated the cost-effectiveness of a hypothetical mobile E-CPR vehicle operated by Queensland Ambulance Service in the state of Queensland, Australia. METHODS: We adapted our published mathematical model to estimate the cost-effectiveness of pre-hospital mobile E-CPR relative to current practice. In the model, a specialised cardiac vehicle with mobile E-CPR capability is deployed to selected OHCA patients, with eligible candidates receiving pre-hospital E-CPR in-field and rapid transport to the closest appropriate centre for in-hospital E-CPR. For comparison, non-candidates receive standard ACLS from a conventional ambulance response. Cost-effectiveness was expressed as Australian dollars ($, 2021 value) per quality-adjusted life year (QALY) gained. RESULTS: Pre-hospital mobile E-CPR improves outcomes compared to current practice at a cost of $27 323 per QALY gained. The cost-effectiveness of pre-hospital mobile E-CPR is sensitive to the assumption around the number of patients who are the targets of the vehicle, with higher patient volume resulting in improved cost-effectiveness. CONCLUSIONS: Pre-hospital E-CPR may be cost-effective. Successful implementation of a pre-hospital E-CPR programme requires substantial planning, training, logistics and operational adjustments.

Medication use among Australian adults with intellectual disability in primary healthcare settings: a cross-sectional study.

BACKGROUND: There is concern about widespread medication use by people with intellectual disability (ID), especially psychotropic and anticonvulsant agents. However, there is sparse information on prescribing patterns in Australia. METHOD: This cross-sectional study was conducted between 2000 and 2002 among adults with ID who live in the community in Brisbane, Australia. Medication data were extracted from a health screening tool. Demographic and medical data were collected from telephone interviews and medical records. RESULTS: Of 117 participants, 35% were prescribed psychotropic medications, most commonly antipsychotics, and 26% anticonvulsants. Complementary medications (vitamins, minerals, amino acids, fish oil, and herbal products) were used by 29% of participants. After adjusting for potentially confounding variables, psychotropic medication use was significantly associated with having a psychiatric illness (adjusted odds ratio = 4.6, 95% CI [1.0, 20.6]) and challenging behaviours (4.4, [1.1, 17.3]). CONCLUSIONS: People with ID use a broad range of medications. Psychotropic medications continue to be the most predominant agents prescribed for this population. Psychotropic medication use is positively associated with having a psychiatric illness and challenging behaviours.

Epidemiology and survival outcomes of out-of-hospital cardiac arrest following volatile substance use in Queensland, Australia.

INTRODUCTION: The deliberate inhalation of volatile substances for their psychotropic properties is a recognised public health issue that can precipitate sudden death. This study aimed to describe the epidemiological characteristics and survival outcomes of patients with out-of-hospital cardiac arrests following volatile substance use. METHODS: We conducted a retrospective cohort analysis of all out-of-hospital cardiac arrest attended by the Queensland Ambulance Service over a ten-year period (2012-2021). Incidents were extracted from the Queensland Ambulance Service cardiac arrest registry, which collects clinical information using the Utstein-style guidelines and linked hospital data. RESULTS: During the study period, 52,102 out-of-hospital cardiac arrests were attended, with 22 (0.04%) occurring following volatile substance use. The incidence rate was 0.04 per 100,000 population, with no temporal trends identified. The most commonly used product was deodorant cans (19/22), followed by butane canisters (2/22), and nitrous oxide canisters (1/22). The median age of patients was 15 years (interquartile range 13-23), with 14/22 male and 8/22 Indigenous Australians. Overall, 16/22 patients received a resuscitation attempt by paramedics. Of these, 12/16 were bystander witnessed, 10/16 presented in an initial shockable rhythm, and 9/16 received bystander chest compressions. The rates of event survival, survival to hospital discharge, and survival with good neurological outcome (Cerebral Performance Category 1-2) were 69% (11/16, 95% CI 41-89%), 38% (6/16, 95% CI 15-65%) and 31% (5/16, 11-59%), respectively. Eight patients in the paramedic-treated cohort that used hydrocarbon-based products were administered epinephrine during resuscitation. Of these, none subsequently survived to hospital discharge. In contrast, all six patients that did not receive epinephrine survived to hospital discharge, with 5/6 having a good neurological outcome. CONCLUSION: Out-of-hospital cardiac arrest following volatile substance use is rare and associated with relatively favourable survival rates. Patients were predominately aged in their adolescence with Indigenous Australians disproportionately represented.

Effect of a national awareness campaign on ambulance attendances for chest pain and out-of-hospital cardiac arrest.

AIM: Awareness of heart attack symptoms may enhance health-seeking behaviour and prevent premature deaths from out-of-hospital cardiac arrest (OHCA). We sought to investigate the impact of a national awareness campaign on emergency medical service (EMS) attendances for chest pain and OHCA. METHODS: Between January 2005 and December 2017, we included registry data for 97,860 EMS-attended OHCA cases from 3 Australian regions and dispatch data for 1,631,217 EMS attendances for chest pain across 5 Australian regions. Regions were exposed to between 11 and 28 months of television, radio, and print media activity. Multivariable negative binomial models were used to explore the effect of campaign activity on the monthly incidence of EMS attendances for chest pain and OHCA. RESULTS: Months with campaign activity were associated with an 8.8% (IRR 1.09, 95% CI: 1.07, 1.11) increase in the incidence of EMS attendances for chest pain and a 5.6% (IRR 0.94, 95% CI: 0.92, 0.97) reduction in OHCA attendances. Larger intervention effects were associated with increasing months of campaign activity, increasing monthly media spending and media exposure in 2013. In stratified analyses of OHCA cases, the largest reduction in incidence during campaign months was observed for unwitnessed arrests (IRR 0.93, 95% CI: 0.90, 0.96), initial non-shockable arrests (IRR 0.93, 95% CI: 0.90, 0.97) and arrests occurring in private residences (IRR 0.95, 95% CI: 0.91, 0.98). CONCLUSION: A national awareness campaign targeting knowledge of heart attack symptoms was associated with an increase in EMS use for chest pain and a reduction in OHCA incidence and may serve as an effective primary prevention strategy for OHCA.

Cost-effectiveness of extracorporeal cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest: A modelling study.

Background: Extracorporeal cardiopulmonary resuscitation (E-CPR) is a method of CPR that passes the patient's blood through an extracorporeal membrane oxygenation (ECMO) device to provide mechanical haemodynamic and oxygenation support in cardiac arrest patients who are not responsive to conventional CPR (C-CPR). E-CPR is being adopted rapidly worldwide despite the absence of high quality trial data and its substantial cost. Published cost-effectiveness data for E-CPR are scarce. Methods: We developed a mathematical model to estimate the cost-effectiveness of E-CPR relative to C-CPR in adult patients with refractory out-of-hospital cardiac arrest (OHCA). The model was a combination of a decision tree for the acute treatment phase and a Markov model for long-term periods. Cost-effectiveness was evaluated from the Australian health system perspective over lifetime. Cost-effectiveness was expressed as Australian dollars (AUD, 2021 value) per quality-adjusted life year (QALY) gained. Variables were parameterised using published data. Probabilistic and univariate sensitivity analyses were performed. Results: The incremental cost-effectiveness ratio (ICER) of E-CPR was estimated to be AUD 45,716 per QALY gained over lifetime (95% uncertainty range 22,102-292,904). The cost-effectiveness of E-CPR was most sensitive to the outcome of the therapy. Conclusion: E-CPR has median ICER that is below common accepted willingness-to-pay thresholds. Local factors within the health care system need to be considered to determine the feasibility of implementing an effective E-CPR program.

Epidemiology of out-of-hospital cardiac arrests that occur secondary to chemical asphyxiants: A retrospective series.

AIM: To determine the epidemiological characteristics, temporal trends and survival outcomes of OHCAs precipitated by chemical asphyxiation. METHODS: We conducted a retrospective cohort analysis of OHCAs attended by paramedics in Queensland, Australia between 2011 and 2020. Patients were classified into two groups depending on the asphyxiating agent involved; simple (argon, carbon dioxide, helium, liquified petroleum gas, nitrogen) and systemic (carbon monoxide, cyanides, hydrogen sulfide, methemoglobin-inducing substances, smoke inhalation). Incidence rates, characteristics and outcomes were described for the entire cohort and independently for each group, with the groups then compared. Temporal trends of asphyxiant utilisation were also described. RESULTS: During the study period, 50,669 OHCAs were attended, with 551 (1.1%) attributable to chemical asphyxiation. The incidence rate was 1.1 per 100,000 population with no significant temporal changes. Suspected suicide was the primary cause of exposure (-95.8%), with systemic asphyixants the dominant agent reported in comparison to simple agents (66.4% vs 33.6%). Over the 10-year period, events precipitated by carbon monoxide decreased by 26.2% (p for trend < 0.001), helium remained unchanged (p for trend = 0.302) and incidents involving nitrogen increased by 28.7% (p for trend < 0.001). Overall, 14.2% (78/551) of the study cohort received a resuscitation attempt by paramedics with 6.4% of these incidents witnessed and 2.6% involving patients presenting in a shockable rhythm. Survival rates were low, with 6.4% surviving the index event, and 1.3% surviving to hospital discharge with a normal neurocognitive function. CONCLUSION: OHCA precipitated by chemical asphyxiation is relatively infrequent and associated with poor survival outcomes.

SONNET: A Self-Guided Ordinal Regression Neural Network for Segmentation and Classification of Nuclei in Large-Scale Multi-Tissue Histology Images.

Automated nuclei segmentation and classification are the keys to analyze and understand the cellular characteristics and functionality, supporting computer-aided digital pathology in disease diagnosis. However, the task still remains challenging due to the intrinsic variations in size, intensity, and morphology of different types of nuclei. Herein, we propose a self-guided ordinal regression neural network for simultaneous nuclear segmentation and classification that can exploit the intrinsic characteristics of nuclei and focus on highly uncertain areas during training. The proposed network formulates nuclei segmentation as an ordinal regression learning by introducing a distance decreasing discretization strategy, which stratifies nuclei in a way that inner regions forming a regular shape of nuclei are separated from outer regions forming an irregular shape. It also adopts a self-guided training strategy to adaptively adjust the weights associated with nuclear pixels, depending on the difficulty of the pixels that is assessed by the network itself. To evaluate the performance of the proposed network, we employ large-scale multi-tissue datasets with 276349 exhaustively annotated nuclei. We show that the proposed network achieves the state-of-the-art performance in both nuclei segmentation and classification in comparison to several methods that are recently developed for segmentation and/or classification.

Spatiotemporal variation in the risk of out-of-hospital cardiac arrests in Queensland, Australia.

BACKGROUND: Spatiotemporal analysis of out-of-hospital cardiac arrest (OHCA) risk is essential to design targeted public health strategies. Such information is lacking in the state of Queensland and Australia more broadly. METHODS: We developed a spatiotemporal Bayesian model accounting for spatial and temporal dimensions, space-time interactions, and demographic factors. The model was fit to data of all OHCA cases attended by paramedics in Queensland between January 2007 and December 2019. Parameter inference was performed using the integrated nested Laplace approximation method. We estimated and thematically mapped area-year risk of OHCA occurrence for all 78 local government areas (LGAs) in Queensland. RESULTS: We observed spatial variability in OHCA risk among the LGAs. Areas in the north half of the state and two areas in the south exhibited the highest risk; whereas OHCA risk was lowest in the west and south west parts of the state. Demographic factors did not have significant impact on the heterogeneity of risk between the LGAs. An overall trend of modestly decreasing risk of OHCA was found. CONCLUSIONS: This study identified areas of high OHCA risk in Queensland, providing valuable information to guide public health policy and optimise resource allocation. Further research is needed to investigate the specifics of the areas that may explain their risk profile.

Geospatial clustering and modelling provide policy guidance to distribute funding for active TB case finding in Ethiopia.

Tuberculosis (TB) exhibits considerable spatial heterogeneity, occurring in clusters that may act as hubs of community transmission. We evaluated the impact of an intervention targeting spatial TB hotspots in a rural region of Ethiopia. To evaluate the impact of targeted active case finding (ACF), we used a spatially structured mathematical model that has previously been described. From model equilibrium, we simulated the impact of a hotspot-targeted strategy (HTS) on TB incidence ten years from intervention commencement and the associated cost-effectiveness. HTS was also compared with an untargeted strategy (UTS). We used logistic cost-coverage analysis to estimate cost-effectiveness of interventions. At a community screening coverage level of 95 % in a hotspot region, which corresponds to screening 20 % of the total population, HTS would reduce overall TB incidence by 52 % compared with baseline. For UTS to achieve an equivalent effect, it would be necessary to screen more than 80 % of the total population. Compared to the existing passive case detection strategy, the HTS at a CDR of 75 percent in hotspot regions is expected to avert 1,023 new TB cases over ten years saving USD 170 per averted case. Similarly, at the same CDR, the UTS will detect 1316 cases over the same period saving USD 3 per averted TB case. The incremental-cost effectiveness-ratio (ICER) of UTS compared with HTS is USD 582 per averted case corresponding to 293 more TB cases averted at an additional cost of USD 170,700. Where regional TB program spending was capped at current levels, maximum gains in incidence reduction were seen when the regional budget was shared between hotspots and non-hotspot regions in the ratio of 40% : 60%. Our analysis suggests that a spatially targeted strategy is efficient and cost-saving, with the potential for significant reduction in overall TB burden.