Determining the Impact of Heatwaves on Emergency Ambulance Calls in Queensland: A Retrospective Population-Based Study

Heatwaves are a significant and growing threat to the health and well-being of the residents of Queensland, Australia. This threat is increasing due to climate change. Excess heat increases the demand for health services, including ambulance calls, and the purpose of this study was to explore this impact across Queensland. A state-wide retrospective analysis of heatwaves and emergency ‘Triple Zero’ (000) calls to Queensland Ambulance (QAS) from 2010–2019 was undertaken. Call data from the QAS and heatwave data from the Bureau of Meteorology were analysed using a case-crossover approach at the postcode level. Ambulance calls increased by 12.68% during heatwaves. The effect was greatest during low-severity heatwaves (22.16%), followed by severe (14.32%) and extreme heatwaves (1.16%). The impact varied by rurality, with those living in very remote areas and major cities most impacted, along with those of low and middle socioeconomic status during low and severe intensity heat events. Lag effects post-heatwave continued for at least 10 days. Heatwaves significantly increase ambulance call centre workload, so ambulance services must actively prepare resources and personnel to address increases in heatwave frequency, duration, and severity. Communities must be informed of the risks of heatwaves at all severities, particularly low severity, and the sustained risks in the days following a heat event

Recognition of, and attitudes towards, people with depression and psychosis with/without alcohol and other drug problems: Results from a national survey of Australian paramedics

Objective Continuing stigma towards mental health problems means that many individuals—especially men—will first present in crisis, with emergency services often the first point of call. Given this situation, the aims of this paper were to assess paramedics’ ability to recognise, and their attitudes towards, males with clinically defined depression and psychosis with and without comorbid alcohol and other drug (AOD) problems. Methods A cross-sectional national online survey of 1230 paramedics throughout Australia. The survey was based on four vignettes: depression with suicidal thoughts, depression with suicidal thoughts and comorbid alcohol problems, and psychosis with and without comorbid AOD problems. Results Just under half of respondents recognised depression, but this decreased markedly to one-fifth when comorbid AOD problems were added to the vignette. In contrast, almost 90% recognised psychosis, but this decreased to just under 60% when comorbid AOD problems were added. Respondents were more likely to hold stigmatising attitudes towards people in the vignettes with depression and psychosis when comorbid AOD problems were present. Respondents endorsed questionnaire items assessing perceived social stigma more strongly than personal stigma. Desire for social distance was greater in vignettes focusing on psychosis with and without comorbid AOD problems than depression with and without comorbid AOD problems. Conclusions Paramedics need a well-crafted multicomponent response which involves cultural change within their organisations and more education to improve their recognition of, and attitudes towards, clients with mental health and AOD problems. Education should focus on the recognition and care of people with specific mental disorders rather than on mental disorders in general. It is essential that education also focuses on understanding and caring for people with AOD problems. Educational interventions should focus on aligning beliefs about public perceptions with personal beliefs about people with mental disorders and AOD problems. This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial

Defining and recognising clinical deterioration in the prehospital setting (PRECLuDE study): a systematic scoping review

IntroductionEarly identification of high-risk patients in the prehospital environment is crucial as it enables early intervention, transportation, and may determine the trajectory of future care. Although early warning systems (EWS) in-hospital are well established, it remains unclear whether adaptations of these systems can simply be extrapolated to prehospital care. This scoping review aims to explore how the current literature defines and recognises clinical deterioration in the prehospital setting. MethodsIn December 2019, a systematic search of five databases using a combination of terms describing ‘paramedic’, were integrated with terminology relating to ‘recognition’ of ‘clinical deterioration’. Additional reference chaining was also undertaken. ResultsA total of eight papers met the inclusion criteria. Seven out of eight studies included a definition, however these were primarily ad-hoc and fundamentally formed to support the creation of varying EWS. The prevalence of prehospital clinical deterioration is poorly explored in the literature, with only two studies discussing the frequency deterioration (5.1%). Furthermore, studies reported that paramedics were inadequate at identifying clinical deterioration due to medical aetiology by comparison to trauma. Additionally, a number of articles reported an association between clinician experience and recognition of clinical deterioration. As the topic of prehospital clinical deterioration has rapidly moved to focus on the potential implementation of EWS, with few studies providing fundamental description of the concept and its characteristics, there is no standardised operational definition available in the literature. The development of this definition is crucial to assessing clinical deterioration and improving the efficacy of EWS. Not only could this lead to improving early identification of risk factors, but it can lay the foundations for the development of an effective EWS. ConclusionThis review has found that further quality research in this understated space is warranted to increase understanding and early identification of the deteriorating patient, prevent unnecessary harm, and ultimately, improve patient outcomes.

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

Pre-hospital predictors of long-term survival from out-of-hospital cardiac arrest

Objective: To identify predictors of longer-term outcomes from adult out-of-hospital cardiac arrest of presumed cardiac aetiology. Methods: In this retrospective cohort study, three large routinely collected databases were linked: 1)QAS Out-of-Hospital Cardiac (OHCA) Registry; 2)Queensland Hospital Admitted Patient Data Collection; and 3)Queensland Registrar General Death Registry. Participants were adult (18years+) residents of Queensland, who suffered an OHCA of presumed cardiac aetiology and had resuscitation attempted by QAS paramedics between 2002 and 2014. Four mutually exclusive outcomes were analysed: 1) No pre-hospital return of spontaneous circulation (ROSC) sustained to the Emergency Department (ED) or ROSC in ED; 2) Survival< 30 days (Pre-hospital ROSC sustained to ED or ROSC in ED but death within 30 days; 3) survival between 30 and 364 days; and 4) survival to 365 + days. Multinomial logistic regression was used to calculate odds ratios and 95 % confidence intervals. Results: Variables significantly predictive of survival to 365 + days after adjusting for all measured confounders are: an initial shockable rhythm; bystander witnessed events with bystander CPR; paramedic witnessed events; intubation placement; time of day (midday-2.59 pm); and attendance by Critical Care Paramedic (CCP). Conclusion: From a service provision perspective, attendance of a CCP at an OHCA may be an important factor to achieve preferred long-term outcomes. Enhanced experience, exposure and expertise, together with extended clinical practice, may explain this finding

Epidemiology of pre-hospital outcomes of out-of-hospital cardiac arrest in Queensland, Australia

Objective To describe incidence in pre-hospital outcomes of adult out-of-hospital cardiac arrest (OHCA) of presumed cardiac aetiology, attended by Queensland Ambulance Service (QAS) paramedics between 2002 and 2014, by age, gender, geographical remoteness and socio-economic status. Methods The QAS OHCA Registry was used to identify cases, which was then linked with Queensland Hospital Admitted Patient Data Collection and Queensland Death Registry. Population data were obtained for each calendar year by age and gender from the Australian Bureau of Statistics in order to calculate incidence rates. Four mutually exclusive pre-hospital outcomes were analysed: (i) no resuscitation (No-Resus); (ii) resuscitation, no pre-hospital return of spontaneous circulation (No-ROSC); (iii) resuscitation, pre-hospital return of spontaneous circulation not sustained to hospital (Unsustained-ROSC); and (iv) resuscitation, pre-hospital return of spontaneous circulation sustained to hospital (Sustained-ROSC). Results Over the 13 years, there were 30 560 OHCA cases for analyses. Incidence was significantly greater in males than females and incrementally increased with age, for each outcome. Incidence of total OHCA events generally increased as remoteness increased (major cities: 72.39 per 100 000 [95% CI 71.35-73.45]; very remote: 87.01 per 100 000 [95% CI 78.03-95.98]). There was an inverse association between incidence of OHCA events and socio-economic status (SEIFA 1 and 2: 81.34 per 100 000 [95% CI 79.28-83.40]; SEIFA 9 and 10: 61.57 per 100 000 [95% CI 59.67-63.46]). Conclusion Rural-specific strategies should be continued. Prevention and management strategies for OHCA targeting lower socio-economic groups require focus

Epidemiology of pre‐hospital outcomes of out‐of‐hospital cardiac arrest in Queensland, Australia

Objective To describe incidence in pre-hospital outcomes of adult out-of-hospital cardiac arrest (OHCA) of presumed cardiac aetiology, attended by Queensland Ambulance Service (QAS) paramedics between 2002 and 2014, by age, gender, geographical remoteness and socio-economic status. Methods The QAS OHCA Registry was used to identify cases, which was then linked with Queensland Hospital Admitted Patient Data Collection and Queensland Death Registry. Population data were obtained for each calendar year by age and gender from the Australian Bureau of Statistics in order to calculate incidence rates. Four mutually exclusive pre-hospital outcomes were analysed: (i) no resuscitation (No-Resus); (ii) resuscitation, no pre-hospital return of spontaneous circulation (No-ROSC); (iii) resuscitation, pre-hospital return of spontaneous circulation not sustained to hospital (Unsustained-ROSC); and (iv) resuscitation, pre-hospital return of spontaneous circulation sustained to hospital (Sustained-ROSC). Results Over the 13 years, there were 30 560 OHCA cases for analyses. Incidence was significantly greater in males than females and incrementally increased with age, for each outcome. Incidence of total OHCA events generally increased as remoteness increased (major cities: 72.39 per 100 000 [95% CI 71.35-73.45]; very remote: 87.01 per 100 000 [95% CI 78.03-95.98]). There was an inverse association between incidence of OHCA events and socio-economic status (SEIFA 1 and 2: 81.34 per 100 000 [95% CI 79.28-83.40]; SEIFA 9 and 10: 61.57 per 100 000 [95% CI 59.67-63.46]). Conclusion Rural-specific strategies should be continued. Prevention and management strategies for OHCA targeting lower socio-economic groups require focus

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.</p

Long-term outcomes of adult out-of-hospital cardiac arrest in Queensland, Australia (2002–2014): incidence and temporal trends

Objective To describe annual incidence and temporal trends (2002-2014) in incidence of long-term outcomes of adult out-of-hospital cardiac arrest (OHCA) of presumed cardiac aetiology attended by Queensland Ambulance Service (QAS) paramedics, by age, gender, geographical remoteness and socioeconomic status (SES). Methods This is a retrospective cohort study. Cases were identified using the QAS OHCA Registry and were linked with entries in the Queensland Hospital Admitted Patient Data Collection and the Queensland Registrar General Death Registry. Population data were obtained from the Australian Bureau of Statistics to calculate incidence. Inclusion criteria were adult (18+ years) residents of Queensland who suffered OHCA of presumed cardiac aetiology and survived to hospital admission. Analyses were undertaken by three mutually exclusive outcomes: (1) survival to less than 30 days (Surv<30 days); (2) survival from 30 to 364 days (Surv30-364 days); and (3) survival to 365 days or more (Surv365+ days). Incidence rates were calculated for each year by gender, age, remoteness and SES. Temporal trends were analysed. Results Over the 13 years there were 4393 cases for analyses. The incidence of total admitted events (9.72-10.13; p<0.01), Surv30-364 days (0.18-0.42; p<0.05) and Surv365+ days (1.94-4.02; p<0.001) increased significantly over time; no trends were observed for Surv<30 days. An increase in Surv365+ days over time was observed in all remoteness categories and most SES categories. Conclusion Evidence suggests that implemented strategies to improve outcomes from OHCA have been successful and penetrated groups living in more remote locations and the lower socioeconomic groups. These populations still require focus. Ongoing reporting of long-term outcomes from OHCA should be undertaken using population-based incidence