Ambulance Services Attendance for Mental Health and Overdose Before and During COVID-19 in Canada and the United Kingdom: Interrupted Time Series Study

BACKGROUND

The COVID-19 pandemic impacted mental health and health care systems worldwide.

OBJECTIVE

This study examined the COVID-19 pandemic's impact on ambulance attendances for mental health and overdose, comparing similar regions in the United Kingdom and Canada that implemented different public health measures.

METHODS

An interrupted time series study of ambulance attendances was conducted for mental health and overdose in the United Kingdom (East Midlands region) and Canada (Hamilton and Niagara regions). Data were obtained from 182,497 ambulance attendance records for the study period of December 29, 2019, to August 1, 2020. Negative binomial regressions modeled the count of attendances per week per 100,000 population in the weeks leading up to the lockdown, the week the lockdown was initiated, and the weeks following the lockdown. Stratified analyses were conducted by sex and age.

RESULTS

Ambulance attendances for mental health and overdose had very small week-over-week increases prior to lockdown (United Kingdom: incidence rate ratio [IRR] 1.002, 95% CI 1.002-1.003 for mental health). However, substantial changes were observed at the time of lockdown; while there was a statistically significant drop in the rate of overdose attendances in the study regions of both countries (United Kingdom: IRR 0.573, 95% CI 0.518-0.635 and Canada: IRR 0.743, 95% CI 0.602-0.917), the rate of mental health attendances increased in the UK region only (United Kingdom: IRR 1.125, 95% CI 1.031-1.227 and Canada: IRR 0.922, 95% CI 0.794-1.071). Different trends were observed based on sex and age categories within and between study regions.

CONCLUSIONS

The observed changes in ambulance attendances for mental health and overdose at the time of lockdown differed between the UK and Canada study regions. These results may inform future pandemic planning and further research on the public health measures that may explain observed regional differences.

The COVID-19 ambulance response assessment (CARA) study: a national survey of ambulance service healthcare professionals' preparedness and response to the COVID-19 pandemic

Background

The COVID-19 pandemic placed significant demand on the NHS, including ambulance services, but it is unclear how this affected ambulance service staff and paramedics in other clinical settings (e.g. urgent and primary care, armed services, prisons). This study aimed to measure the self-perceived preparedness and impact of the first wave of the pandemic on paramedics' psychological stress and perceived ability to deliver care.

Methods

Ambulance clinicians and paramedics working in other healthcare settings were invited to participate in a three-phase sequential online survey during the acceleration (April 2020), peak (May 2020) and deceleration (September/October 2020) phases of the first wave of COVID-19 in the United Kingdom. Recruitment used social media, Trust internal bulletins and the College of Paramedics' communication channels, employing a convenience sampling strategy. Data were collected using purposively developed open- and closed-ended questions and the validated general health questionnaire-12 (GHQ-12). Data were analysed using multi-level linear and logistic regression models.

Results

Phase 1 recruited 3717 participants, reducing to 2709 (73%) by phase 2 and 2159 (58%) by phase 3. Participants were mostly male (58%, n = 2148) and registered paramedics (n = 1992, 54%). Mean (standard deviation) GHQ-12 scores were 16.5 (5.2) during phase 1, reducing to 15.2 (6.7) by phase 3. A total of 84% of participants (n = 3112) had a GHQ-12 score ≥ 12 during the first phase, indicating psychological distress. Participants that had higher GHQ-12 scores were feeling unprepared for the pandemic, and reported a lack of confidence in using personal protective equipment and managing cardiac arrests in confirmed or suspected COVID-19 patients.

Conclusions

Most participants reported psychological distress, the reasons for which are multi-factorial. Ambulance managers need to be aware of the risks to staff mental health and take action to mitigate these, to support staff in the delivery of unscheduled, emergency and urgent care under these additional pressures.

Route of drug administration in out-of-hospital cardiac arrest: A protocol for a randomised controlled trial (PARAMEDIC-3)

Aims

The PARAMEDIC-3 trial evaluates the clinical and cost-effectiveness of an intraosseous first strategy, compared with an intravenous first strategy, for drug administration in adults who have sustained an out-of-hospital cardiac arrest.

Methods

PARAMEDIC-3 is a pragmatic, allocation concealed, open-label, multi-centre, superiority randomised controlled trial. It will recruit 15,000 patients across English and Welsh ambulance services. Adults who have sustained an out-of-hospital cardiac arrest are individually randomised to an intraosseous access first strategy or intravenous access first strategy in a 1:1 ratio through an opaque, sealed envelope system. The randomised allocation determines the route used for the first two attempts at vascular access. Participants are initially enrolled under a deferred consent model.The primary clinical-effectiveness outcome is survival at 30-days. Secondary outcomes include return of spontaneous circulation, neurological functional outcome, and health-related quality of life. Participants are followed-up to six-months following cardiac arrest. The primary health economic outcome is incremental cost per quality-adjusted life year gained.

Conclusion

The PARAMEDIC-3 trial will provide key information on the clinical and cost-effectiveness of drug route in out-of-hospital cardiac arrest.Trial registration: ISRCTN14223494, registered 16/08/2021, prospectively registered.

Development of indicators for avoidable emergency medical service calls by mapping paramedic clinical impression codes to ambulatory care sensitive conditions and mental health conditions in the UK and Canada

OBJECTIVE

Paramedic assessment data have not been used for research on avoidable calls. Paramedic impression codes are designated by paramedics on responding to a 911/999 medical emergency after an assessment of the presenting condition. Ambulatory care sensitive conditions (ACSCs) are non-acute health conditions not needing hospital admission when properly managed. This study aimed to map the paramedic impression codes to ACSCs and mental health conditions for use in future research on avoidable 911/999 calls.

DESIGN

Mapping paramedic impression codes to existing definitions of ACSCs and mental health conditions.

SETTING

East Midlands Region, UK and Southern Ontario, Canada.

PARTICIPANTS

Expert panel from the UK-Canada Emergency Calls Data analysis and GEospatial mapping (EDGE) Consortium.

RESULTS

Mapping was iterative first identifying the common ACSCs shared between the two countries then identifying the respective clinical impression codes for each country that mapped to those shared ACSCs as well as to mental health conditions. Experts from the UK-Canada EDGE Consortium contributed to both phases and were able to independently match the codes and then compare results. Clinical impression codes for paramedics in the UK were more extensive than those in Ontario. The mapping revealed some interesting inconsistencies between paramedic impression codes but also demonstrated that it was possible.

CONCLUSION

This is an important first step in determining the number of ASCSs and mental health conditions that paramedics attend to, and in examining the clinical pathways of these individuals across the health system. This work lays the foundation for international comparative health services research on integrated pathways in primary care and emergency medical services.

An early warning precision public health approach for assessing COVID-19 vulnerability in the UK: the Moore-Hill Vulnerability Index (MHVI)

BACKGROUND

Most COVID-19 vulnerability indices rely on measures that are biased by rates of exposure or are retrospective like mortality rates that offer little opportunity for intervention. The Moore-Hill Vulnerability Index (MHVI) is a precision public health early warning alternative to traditional infection fatality rates that presents avenues for mortality prevention.

METHODS

We produced an infection-severity vulnerability index by calculating the proportion of all recorded positive cases that were severe and attended by ambulances at small area scale for the East Midlands of the UK between May 2020 and April 2022. We produced maps identifying regions with high and low vulnerability, investigated the accuracy of the index over shorter and longer time periods, and explored the utility of the MHVI compared to other common proxy measures and indices. Analysis included exploring the correlation between our novel index and the Index of Multiple Deprivation (IMD).

RESULTS

The MHVI captures geospatial dynamics that single metrics alone often overlook, including the compound health challenges associated with disadvantaged and declining coastal towns inhabited by communities with post-industrial health legacies. A moderate negative correlation between MHVI and IMD reflects spatial analysis which suggests that high vulnerability occurs in affluent rural as well as deprived coastal and urban communities. Further, the MHVI estimates of severity rates are comparable to infection fatality rates for COVID-19.

CONCLUSIONS

The MHVI identifies regions with known high rates of poor health outcomes prior to the pandemic that case rates or mortality rates alone fail to identify. Pre-hospital early warning measures could be utilised to prevent mortality during a novel pandemic.

Trends in use of intraosseous and intravenous access in out-of-hospital cardiac arrest across English ambulance services: A registry-based, cohort study

INTRODUCTION

The optimum route for drug administration in cardiac arrest is unclear. Recent data suggest that use of the intraosseous route may be increasing. This study aimed to explore changes over time in use of the intraosseous and intravenous drug routes in out-of-hospital cardiac arrest in England.

METHODS

We extracted data from the UK Out-of-Hospital Cardiac Arrest Outcomes registry. We included adult out-of-hospital cardiac arrest patients between 2015-2020 who were treated by an English Emergency Medical Service that submitted vascular access route data to the registry. The primary outcome was any use of the intraosseous route during cardiac arrest. We used logistic regression models to describe the association between time (calendar month) and intraosseous use.

RESULTS

We identified 75,343 adults in cardiac arrest treated by seven Emergency Medical Service systems between January 2015 and December 2020. The median age was 72 years, 64% were male and 23% presented in a shockable rhythm. Over the study period, the percentage of patients receiving intraosseous access increased from 22.8% in 2015 to 42.5% in 2020. For each study-month, the odds of receiving any intraosseous access increased by 1.019 (95% confidence interval 1.019 to 1.020, p < 0.001). This observed effect was consistent across sensitivity analyses. We observed a corresponding decrease in use of intravenous access.

CONCLUSION

In England, the use of intraosseous access in out-of-hospital cardiac arrest has progressively increased over time. There is an urgent need for randomised controlled trials to evaluate the clinical effectiveness of the different vascular access routes in cardiac arrest.

Community First Responders' Contribution to Emergency Medical Service Provision in the United Kingdom

STUDY OBJECTIVE

We aimed to investigate community first responders' contribution to emergency care provision in terms of number, rate, type, and location of calls and characteristics of patients attended.

METHODS

We used a retrospective observational design analyzing routine data from electronic clinical records from 6 of 10 ambulance services in the United Kingdom during 2019. Descriptive statistics, including numbers and frequencies, were used to illustrate characteristics of incidents and patients that the community first responders attended first in both rural and urban areas.

RESULTS

The data included 4.5 million incidents during 1 year. The community first responders first attended a higher proportion of calls in rural areas compared with those in urban areas (3.90% versus 1.48 %). In rural areas, the community first responders also first attended a higher percentage of the most urgent call categories, 1 and 2. The community first responders first attended more than 9% of the total number of category 1 calls and almost 5% of category 2 calls. The community first responders also attended a higher percentage of the total number of cardiorespiratory and neurological/endocrine conditions. They first attended 6.5% of the total number of neurological/endocrine conditions and 5.9% of the total number of cardiorespiratory conditions. Regarding arrival times in rural areas, the community first responders attended higher percentages (more than 6%) of the total number of calls that had arrival times of less than 7 minutes or more than 60 minutes.

CONCLUSION

In the United Kingdom, community first responders contribute to the delivery of emergency medical services, particularly in rural areas and especially for more urgent calls. The work of community first responders has expanded from their original purpose-to attend to out-of-hospital cardiac arrests. The future development of community first responders' schemes should prioritize training for a range of conditions, and further research is needed to explore the contribution and potential future role of the community first responders from the perspective of service users, community first responders' schemes, ambulance services, and commissioners.

Optimising ambulance conveyance rates and staff costs by adjusting proportions of rapid-response vehicles and dual-crewed ambulances: an economic decision analytical modelling study

AIM

To model optimum proportions of dual-crewed ambulances (DCAs) and rapid-response vehicles (RRVs) in Ambulance Trusts with a view to generating a policy brief for one Ambulance Trust and a modelling tool for other Trusts on the strategic procurement and allocation of emergency vehicle (EV) resources.

METHODS

Historical EV assignments for 12 months of emergency calls in 2019 were provided by an NHS Ambulance Trust and analysed for backup, see and treat, and patient to hospital conveyance. Unit costs were derived for paramedics and technicians using Agenda for Change pay rates. Time cycles were assigned for RRV and DCA attendances and unit costs assigned to these. Information was put into a decision analytical model to estimate the costs and numbers of vehicles attending incidents based on relative proportions of available RRVs and DCAs.

RESULTS

Of 711 992 calls attended by 837 107 EVs, 514 766 (72.3%) required at least one emergency department conveyance. The rate of conveyance was significantly lower when RRVs arrived first on the scene. 27 883 out of 529 693 (5.3%) DCAs first arriving at an incident required some backup, and this was also factored into the model. Modelling demonstrated high conveyance rates were counterproductive when increasing the relative proportions of RRVs to DCAs. For example, with conveyance rates of 65%, increasing the RRVs increased the cost and numbers of vehicles attending per incident. At lower conveyance rates, however, there was a levelling around 30% where it could become cost-effective to increase the relative proportions of RRVs to DCAs.

CONCLUSION

At current overall conveyance rates, there is no benefit in increasing the relative proportions of RRVs to DCAs unless additional benefits can be realised that bring the conveyance rates down.

Model-based economic evaluation of the effectiveness of "'Hypos' can strike twice", a leaflet-based ambulance clinician referral intervention to prevent recurrent hypoglycaemia

"'Hypos' can strike twice" (HS2) is a pragmatic, leaflet-based referral intervention designed for administration by clinicians of the emergency medical services (EMS) to people they have attended and successfully treated for hypoglycaemia. Its main purpose is to encourage the recipient to engage with their general practitioner or diabetic nurse in order that improvements in medical management of their diabetes may be made, thereby reducing their risk of recurrent hypoglycaemia. Herein we build a de novo economic model for purposes of incremental analyses to compare, in 2018-19 prices, HS2 against standard care for recurrent hypoglycaemia in the fortnight following the initial attack from the perspective of the UK National Health Service (NHS). We found that per patient NHS costs incurred by people receiving the HS2 intervention over the fortnight following an initial hypoglycaemia average £49.79, and under standard care costs average £40.50. Target patient benefit assessed over that same period finds the probability of no recurrence of hypoglycaemia averaging 42.4% under HS2 and 39.4% under standard care, a 7.6% reduction in relative risk. We find that implementing HS2 will cost the NHS an additional £309.36 per episode of recurrent hypoglycaemia avoided. Contrary to the favourable support offered in Botan et al., we conclude that in its current form the HS2 intervention is not a cost-effective use of NHS resources when compared to standard NHS care in reducing the risk of hypoglycaemia recurring within a fortnight of an initial attack that was resolved at-scene by EMS ambulance clinicians.

PP21 Factors affecting community first responders’ role in rural emergencies: a qualitative interview study

Background

Community first responders (CFRs) are volunteers delivering emergency medical assistance and maintaining a patient’s condition until an ambulance arrives. Previous research has highlighted the CFR role and relationships, motivations, practice and perceptions, and need for mental health support. However, factors influencing CFR practise in the field are a relatively underexplored area. We aimed to explore the factors embedded in CFR implementation processes that either facilitated or hindered CFRs’ activities and practice in the UK.

Method

In a qualitative study, we conducted interviews with CFRs and CFR leads, paramedics and ambulance clinicians, commissioners, patients and relatives across six English ambulance service regions. Thematic analysis, supported by NVivo, enabled the identification codes and themes.

Result

Overall, 47 participants were interviewed including CFR leads (15), CFRs (21), ambulance staff (4), and commissioners (2) from six ambulance services with patients and relatives (5) from the same regions. The findings revealed multi-layered factors influencing effective CFR functioning at three levels, namely individual, institutional, and societal. CFRs’ local expertise helped them to navigate operational challenges. Use of a personal vehicle and navigation software aided CFRs’ ability to respond promptly. Continuing training improved CFRs’ skills. CFR functioning was facilitated by positive relationships with ambulance crews. Identification and recognition by patients were important and aided by wearing uniforms. Community support was a facilitator for CFR activities in rural areas. In contrast, limited communication in remote regions, long waits for an ambulance, and reliance on community donations impeded CFRs’ care function. Volunteer shortages and lack of access to a blue light while using trusts’ car hindered CFRs’ ability to respond quickly. Negative relationships with ambulance crews also hampered CFRs’ involvement.

Conclusion

This study highlights factors associated with effective CFR functioning and the requirement for supportive institutional and societal contexts for CFRs to assist patients in medical emergencies.

04 People with diabetes and ambulance staff perceptions of a booklet-based intervention for diabetic hypoglycaemia, ‘hypos can strike twice’: a mixed methods process evaluation

Background

Hypoglycaemia is a potentially serious condition, characterised by lower-than-normal blood glucose levels, common in people with diabetes (PWD). It can be prevented and self-managed if expert support (e.g., education on lifestyle and treatment) is provided. Our aim was to conduct a process evaluation to investigate how ambulance staff and PWD perceived the ‘Hypos can strike twice’ booklet-based ambulance clinician intervention.

Methods

We used an explanatory sequential design with a self-administered questionnaire study followed by interviews of PWD and ambulance staff. We followed the Medical Research Council framework for process evaluations of complex interventions to guide data collection and analysis. Following descriptive analysis and exploratory factor analysis, multiple regression models were fitted to identify demographic predictors of overall and subscale scores.

Results

113 ambulance staff members and 46 PWD completed the survey. We conducted interviews with four ambulance staff members and five PWD who had been attended by an ambulance for a hypoglycaemic event. Overall, there were positive attitudes to the intervention from both ambulance staff and PWD. Although the intervention was not always implemented, most staff members and PWD found the booklet informative, easy to read and to use/explain. PWD who completed the survey reported that receiving the booklet reminded and/or encouraged them to test their blood glucose more often, adjust their diet, and have a chat/check up with their diabetes consultant. Interviewed PWD felt that the booklet intervention would be more valuable to less experienced patients or those who cannot manage their diabetes well. Participants felt that the intervention could be beneficial but were uncertain about whether it can prevent a second hypoglycaemic event and/or reduce the number of repeat ambulance attendances.

Conclusions

The ‘Hypos may strike twice’ intervention was found to be feasible, acceptable to PWD and staff, prompting reported behaviour change and help-seeking from primary care.

PP45 ‘Every day was a learning curve’: the experience of implementing COVID-19 triage protocols in UK ambulance services – a qualitative study

Background

TRIM is an evaluation of the models used to triage and manage emergency ambulance service care for patients with suspected Covid-19 during the first wave of the pandemic in 2020. We aimed to understand experiences and concerns of clinical and managerial staff about implementation of triage protocols in call centre and on-scene.

Methods

Research paramedics in four study sites across England interviewed purposively selected stakeholders from ambulance services (call handlers, clinical advisors in call centres, clinicians providing emergency response, managers) and ED clinical staff from one hospital per site. Interviews (n=23) were conducted remotely using MS Teams, recorded, and transcribed in full. Analysis generated themes from the implicit and explicit ideas within participants’ accounts, following the six stages of analysis described by Braun and Clarke, conducted by a group of researchers and PPI partners working together.

Results

We identified the following themes:

Constantly changing guidelines – at some points, updates several times a day

The ambulance service as part of the wider healthcare system - changes in other parts of the healthcare system left ambulance services as the default option

Peaks and troughs of demand - demand fluctuated greatly over time, with workload varying across the ambulance service, including an increased role for clinical advisors

A stretched system - resources to respond to patient demand were stretched thinner by staff sickness and isolation, longer job times, and increased handover delays at ED

Emotional load of responding to the pandemic - particularly for call centre staff

Doing the best they can in the face of uncertainty - in the face of a rapidly evolving situation unlike any which ambulance services had faced before

Discussion

Implementing triage protocols in response to the Covid-19 pandemic was a complex and process which had to be actively managed by a range of front line staff, dealing with external pressures and a heavy emotional load.

PP26 Exploring the use of pre-hospital pre-alerts and their impact on patients, ambulance service and emergency department staff: protocol for a mixed methods study

Background

Ambulance clinicians use pre-alert calls to inform receiving emergency departments (EDs) of the arrival of a critically unwell patient that will require a specialised response. Little is known about how a decision to pre-alert is made and how this is communicated and acted upon in the receiving ED. Whilst appropriate use of pre-alerts benefits patient care, their overuse carries a risk of harm or opportunity costs. The impact of pre-alerts on ambulance clinicians, ED staff and patients is not currently well understood.

Methods

We are conducting a mixed methods study with five inter-related work packages. We will analyse 12 months of routine data from ambulance pre-alerts in three regions to identify factors in the variation of pre-alert use, including pre-hospital decision-making. We will undertake a national online Qualtrics survey of ambulance clinician perspectives and experience of pre-alerts. We will explore the impacts of a pre-alert on staff, ED facilities and the patient using semi-structured interviews with ambulance clinicians, ED staff, patients and carers and undertake non-participant observation of ED pre-alert response.

Expected Results

We will describe current pre-alert practice using 12 months’ data for 3 Ambulance Services, including volume and types of pre-alerts. We will identify specific conditions or patient groups for whom pre-alerts are most likely to lead to change in clinical practice, or for whom action is unlikely to provide benefit. We will hold a feedback workshop in which we will share and discuss our findings with key stakeholders.

Conclusions

Current variation in pre-alert processes, both pre-hospital and in-hospital and the impact on patient care is not understood. The outputs of this study will establish an evidence base to update national guidance for pre-alert practice and identify areas of good pre-alert practice for both ambulance service and Emergency Department staff.

EP10 Community first responders‘ contribution to rural emergency medical service provision in the UK

Background

Community First Responders (CFRs) are volunteers dispatched by Emergency Medical Services (EMS) to potentially life-threatening emergencies to provide care until the ambulance staff arrive. Previous qualitative research described CFRs’ role, perceptions, and motivations, but quantitative evidence on their contribution to rural healthcare provision is lacking. We aimed to investigate the number, types, and location of calls (rural or urban), and characteristics of patients attended.

Methods

We used a retrospective observational design analysing routine data from six of ten ambulance services in England during 2019. Descriptive statistics were used to directly compare incidents where CFRs attended first with attendances from ambulance staff. A multiple logistic regression model was used to identify the main predictors of CFR attendance.

Results

The data included 4.5 million incidents over one year. CFRs attended first a significantly higher proportion of calls in rural areas compared to urban areas (3.90% vs 1.48%, p<0.05). The main predictors of CFR presence were rurality (Odds Ratio [OR] 2.05, 95% Confidence Interval [CI] 1.99-2.11, p<0.001), conditions including cardiorespiratory (OR 9.20, 95%CI 5.08-16.64, p<0.001) or neurological/endocrine (OR 9.26, 95%CI 5.12-16.77, p<0.001) and the most urgent call category 1 (OR 5.19, 95%CI 3.86-6.99, p<0.001) and call category 2 (OR 4.44, 95%CI 3.31-5.96 p<0.001). CFRs were also less likely to attend patients from minority ethnic backgrounds, those younger than 39 years, and incidents in more deprived areas.

Conclusions

CFRs play an important role in EMS delivery, supporting the work of ambulance services, especially in rural areas. The work of CFRs has expanded from its original purpose to attend out-of-hospital cardiac arrest to more types of emergencies. Future development of CFR schemes should prioritise training for a range of conditions, and access to more deprived and ethnically diverse areas.

Mental health emergencies attended by ambulances in the United Kingdom and the implications for health service delivery: A cross-sectional study

OBJECTIVE

In the context of increasing demand for ambulance services, emergency mental health cases are among the most difficult for ambulance clinicians to attend, partly because the cases often involve referring patients to other services. We describe the characteristics of mental health emergencies in the East Midlands region of the United Kingdom. We explore the association between 999 (i.e. emergency) call records, the clinical impressions of ambulance clinicians attending emergencies and the outcomes of ambulance attendance. We consider the implications of our results for optimizing patient care and ambulance service delivery.

METHODS

We conducted a retrospective observational study of records of all patients experiencing mental health emergencies attended by ambulances between 1 January 2018 and 31 July 2020. The records comprised details of 103,801 '999' calls (Dispatch), the preliminary diagnoses by ambulance clinicians on-scene (Primary Clinical Impression) and the outcomes of ambulance attendance for patients (Outcome).

RESULTS

A multinomial regression analysis found that model fit with Outcome data was improved with the addition of Dispatch and Primary Clinical Impression categories compared to the fit for the model containing only the intercept and Outcome categories (Chi-square = 18,357.56, df = 180, p < 0.01). Dispatch was a poor predictor of Primary Clinical impression. The most common predictors of Outcome care pathways other than 'Treated and transported' were records of respiratory conditions at Dispatch and anxiety reported by clinicians on-scene.

CONCLUSIONS

Drawing on the expertise of mental health specialists may help '999' dispatchers distinguish between physical and mental health emergencies and refer patients to appropriate services earlier in the response cycle. Further investigation is needed to determine if training Dispatch operatives for early triage and referral can be appropriately managed without compromising patient safety.

Evaluation of the effectiveness and costs of inhaled methoxyflurane versus usual analgesia for prehospital injury and trauma: non-randomised clinical study

BACKGROUND

We aimed to investigate clinical benefits and economic costs of inhaled methoxyflurane when used by ambulance staff for prehospital emergency patients with trauma. Comparison is to usual analgesic practice (UAP) in the UK in which patient records were selected if treatment had been with Entonox® or intravenous morphine or intravenous paracetamol.

METHODS

Over a 12-month evaluation period, verbal numerical pain scores (VNPS) were gathered from adults with moderate to severe trauma pain attended by ambulance staff trained in administering and supplied with methoxyflurane. Control VNPS were obtained from ambulance database records of UAP in similar patients for the same period. Statistical modelling enabled comparisons of methoxyflurane to UAP, where we employed an Ordered Probit panel regression model for pain, linked by observational rules to VNPS.

RESULTS

Overall, 96 trained paramedics and technicians from the East Midlands Ambulance Service NHS Trust (EMAS) prepared 510 doses of methoxyflurane for administration to a total of 483 patients. Comparison data extracted from the EMAS database of UAP episodes involved: 753 patients using Entonox®, 802 patients using intravenous morphine, and 278 patients using intravenous paracetamol. Modelling results included demonstration of faster pain relief with inhaled methoxyflurane (all p-values < 0.001). Methoxyflurane's time to achieve maximum pain relief was estimated to be significantly shorter: 26.4 min (95%CI 25.0-27.8) versus Entonox® 44.4 min (95%CI 39.5-49.3); 26.5 min (95%CI 25.0-27.9) versus intravenous morphine 41.8 min (95%CI 38.9-44.7); 26.5 min (95%CI 25.1-28.0) versus intravenous paracetamol 40.8 (95%CI 34.7-46.9). Scenario analyses showed that durations spent in severe pain were significantly less for methoxyflurane. Costing scenarios showed the added benefits of methoxyflurane were achieved at higher cost, eg versus Entonox® the additional cost per treated patient was estimated to be £12.30.

CONCLUSION

When administered to adults with moderate or severe pain due to trauma inhaled methoxyflurane reduced pain more rapidly and to a greater extent than Entonox® and parenteral analgesics. Inclusion of inhaled methoxyflurane to the suite of prehospital analgesics provides a clinically useful addition, but one that is costlier per treated patient.

Characterizing Unusual Spatial Clusters of Male Mental Health Emergencies Occurring During the First National COVID-19 "Lockdown" in the East Midlands Region, UK: A Geospatial Analysis of Ambulance 999 Data

The widespread psychological effects of contagion mitigation measures associated with the novel coronavirus disease 2019 (COVID-19) are well known. Phases of “lockdown” have increased levels of anxiety and depression globally. Most research uses methods such as self-reporting that highlight the greater impact of the pandemic on the mental health of females. Emergency medical data from ambulance services may be a better reflection of male mental health. We use ambulance data to identify unusual clusters of high rates of male mental health emergencies occurring in the East Midlands of the United Kingdom during the first national “lockdown” and to explore factors that may explain clusters. Analysis of more than 5,000 cases of male mental health emergencies revealed 19 unusual spatial clusters. Binary logistic regression analysis (χ² = 787.22, df = 20, p ≤ .001) identified 16 factors that explained clusters, including proximity to “healthy” features of the physical landscape, urban and rural dynamics, and socioeconomic condition. Our findings suggest that the factors underlying vulnerability of males to severe mental health conditions during “lockdown” vary within and between rural and urban spaces, and that the wider “hinterland” surrounding clusters influences the social and physical access of males to services that facilitate mental health support. Limitations on social engagement to mitigate effects of the pandemic are likely to continue. Our approach could inform delivery of emergency services and the development of community-level services to support vulnerable males during periods of social isolation.

Ambulance attendance for substance and/or alcohol use in a pandemic: Interrupted time series analysis of incidents

INTRODUCTION

The ambulance attendance for substance and/or alcohol use in a pandemic (ASAP) study explores incidents during the COVID-19 lockdown in the East Midlands region of the United Kingdom (23 March-4 July 2020).

METHOD

Retrospective cross-sectional count per day of ambulance attendances from the East Midlands Ambulance Service Trust. Ambulance attendances relating to alcohol or other drug use in the year prior, during lockdown and weeks following, were examined using interrupted time series analysis by patient demographics and geographical location.

RESULTS

A total of 36 104 records were identified (53.7% male, 84.5% ethnicity classified as White, mean age 38.4 years). A significant drop in the number of attendances per day at the start of lockdown (-25.24, confidence interval - 38.16, -12.32) was observed, followed by a gradual increase during the ongoing lockdown period (0.36, confidence interval 0.23, 0.46). Similar patterns were found across genders, age groups 16-64 and urban/rural locations.

DISCUSSION AND CONCLUSION

The pattern of ambulance attendances for alcohol or other drug use changed during the COVID-19 lockdown period. Lockdown significantly affected the use of ambulances for incidents involving alcohol or other drug use, impacting on health-care services. Further research into hazardous use of alcohol or other drugs during the lockdown periods is needed to inform policy, planning and public health initiatives.

Exploring the Impact of the COVID-19 Pandemic on Male Mental Health Emergencies Attended by Ambulances During the First National "Lockdown" in the East Midlands of the United Kingdom

The novel coronavirus disease 2019 (COVID-19) pandemic and associated mitigation strategies such as “lockdown” are having widespread adverse psychological effects, including increased levels of anxiety and depression. Most research using self-reported data highlights the pandemic’s impact on the psychological well-being of females, whereas data for mental health emergency presentations may reflect the impact on male mental health more accurately. We analyzed records of male mental health emergencies occurring in the East Midlands of the United Kingdom during the first national “lockdown.” We computed two binary logistic regression models to (a) compare male mental health emergencies occurring during “lockdown,” 2020 (5,779) with those occurring in the same period in 2019 (N = 4,744) and (b) compare male (N = 5,779) and female (N = 7,695) mental health emergencies occurring during “lockdown.” Comparisons considered the characteristics of mental health emergencies recorded by ambulance clinicians (Primary Impressions), and the socioeconomic characteristics of communities where emergencies use the Index of Multiple Deprivation. We found that during “lockdown,” male emergencies were more likely to involve acute anxiety (odds ratio [OR]: 1.42) and less likely to involve intentional drug overdose (OR: 0.86) or attempted suicide (OR: 0.71) compared with 2019. Compared with females, male emergencies were more likely to involve acute behavioral disturbance (OR: 1.99) and less likely to involve anxiety (OR: 0.67), attempted suicide (OR: 0.83), or intentional drug overdose (OR: 0.76). Compared with 2019, and compared with females, males experiencing mental health emergencies during “lockdown” were more likely to present in areas of high deprivation. Understanding the presentation of male mental health emergencies could inform improved patient care pathways.

An exploration of factors characterising unusual spatial clusters of COVID-19 cases in the East Midlands region, UK: A geospatial analysis of ambulance 999 data

Complex interactions between physical landscapes and social factors increase vulnerability to emerging infections and their sequelae. Relative vulnerability to severe illness and/or death (VSID) depends on risk and extent of exposure to a virus and underlying health susceptibility. Identifying vulnerable communities and the regions they inhabit in real time is essential for effective rapid response to a new pandemic, such as COVID-19. In the period between first confirmed cases and the introduction of widespread community testing, ambulance records of suspected severe illness from COVID-19 could be used to identify vulnerable communities and regions and rapidly appraise factors that may explain VSID. We analyse the spatial distribution of more than 10,000 suspected severe COVID-19 cases using records of provisional diagnoses made by trained paramedics attending medical emergencies. We identify 13 clusters of severe illness likely related to COVID-19 occurring in the East Midlands of the UK and present an in-depth analysis of those clusters, including urban and rural dynamics, the physical characteristics of landscapes, and socio-economic conditions. Our findings suggest that the dynamics of VSID vary depending on wider geographic location. Vulnerable communities and regions occur in more deprived urban centres as well as more affluent peri-urban and rural areas. This methodology could contribute to the development of a rapid national response to support vulnerable communities during emerging pandemics in real time to save lives.

People with diabetes and ambulance staff perceptions of a booklet-based intervention for diabetic hypoglycaemia, "Hypos can strike twice": a mixed methods process evaluation

Background

Hypoglycaemia is a potentially serious condition, characterised by lower-than-normal blood glucose levels, common in people with diabetes (PWD). It can be prevented and self-managed if expert support, such as education on lifestyle and treatment, is provided. Our aim was to conduct a process evaluation to investigate how ambulance staff and PWD perceived the “Hypos can strike twice” booklet-based ambulance clinician intervention, including acceptability, understandability, usefulness, positive or negative effects, and facilitators or barriers to implementation.

Methods

We used an explanatory sequential design with a self-administered questionnaire study followed by interviews of people with diabetes and ambulance staff. We followed the Medical Research Council framework for process evaluations of complex interventions to guide data collection and analysis. Following descriptive analysis (PWD and staff surveys), exploratory factor analysis was conducted to identify staff questionnaire subscales and multiple regression models were fitted to identify demographic predictors of overall and subscale scores.

Results

113 ambulance staff members and 46 PWD completed the survey. We conducted interviews with four ambulance staff members and five PWD who had been attended by an ambulance for a hypoglycaemic event. Based on surveys and interviews, there were positive attitudes to the intervention from both ambulance staff and PWD. Although the intervention was not always implemented, most staff members and PWD found the booklet informative, easy to read and to use or explain. PWD who completed the survey reported that receiving the booklet reminded and/or encouraged them to test their blood glucose more often, adjust their diet, and have a discussion/check up with their diabetes consultant. Interviewed PWD felt that the booklet intervention would be more valuable to less experienced patients or those who cannot manage their diabetes well. Overall, participants felt that the intervention could be beneficial, but were uncertain about whether it might help prevent a second hypoglycaemic event and/or reduce the number of repeat ambulance attendances.

Conclusions

The ‘Hypos may strike twice’ intervention, which had demonstrable reductions in repeat attendances, was found to be feasible, acceptable to PWD and staff, prompting reported behaviour change and help-seeking from primary care.

Trial registration

Registered with ClinicalTrials.gov: NCT04243200 on 27 January 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-022-00583-y.

The effect of the GoodSAM volunteer first-responder app on survival to hospital discharge following out-of-hospital cardiac arrest

AIMS

Bystander cardiopulmonary resuscitation and defibrillation can double survival to hospital discharge in out-of-hospital cardiac arrest. Mobile phone applications, such as GoodSAM, alerting nearby volunteer first-responders about out-of-hospital cardiac arrest could potentially improve bystander cardiopulmonary resuscitation and defibrillation, leading to better patient outcomes. The aim of this study was to determine GoodSAM's effect on survival to hospital discharge following out-of-hospital cardiac arrest.

METHODS AND RESULTS

We collected data from the Out-of-Hospital Cardiac Arrest Outcomes Registry (University of Warwick, UK) submitted by the London Ambulance Service (1 April 2016 to 31 March 2017) and East Midlands Ambulance Service (1 January 2018 to 17 June 2018) and matched out-of-hospital cardiac arrests to GoodSAM alerts. We constructed logistic regression models to determine if there was an association between a GoodSAM first-responder accepting an alert and survival to hospital discharge, adjusting for location type, presenting rhythm, age, gender, ambulance service response time, cardiac arrest witnessed status, and bystander actions. Survival to hospital discharge was 9.6% (393/4196) in London and 7.2% (72/1001) in East Midlands. A GoodSAM first-responder accepted an alert for out-of-hospital cardiac arrest in 1.3% (53/4196) cases in London and 5.4% (51/1001) cases in East Midlands. When a responder accepted an alert, the adjusted odds ratio for survival to hospital discharge was 3.15 (95% CI: 1.19-8.36, P = 0.021) in London and 3.19 (95% CI: 1.17-8.73, P = 0.024) in East Midlands.

CONCLUSION

Alert acceptance was associated with improved survival in both ambulance services. Alert acceptance rates were low, and challenges remain to maximize the potential benefit of GoodSAM.

Rethinking the health implications of society-environment relationships in built areas: An assessment of the access to healthy and hazards index in the context of COVID-19

Urban environments have been evolving to mitigate threats to the health and wellbeing of societies for thousands of years, including establishing open spaces to combat bubonic plague, improving waste management in the 20th century, and more recently retrofitting urban landscapes with green space to promote physical exercise. In the context of the current COVID-19 pandemic there is a need to rethink how societies interact with space in built environments to prevent contagion at the same time as facilitating health behaviours, such as exercise. Previously, we examined the spatial relationship between features of urban landscapes that are commonly considered to be 'hazardous' and 'healthy' and unusual clusters of COVID-19 cases in the East Midlands of the UK using ambulance data. Here, we consider the nature of social engagement that these features of urban landscapes facilitate and identify society-environment interactions that may increase risk of exposure to the virus. In some cases, spaces that are commonly thought to promote health behaviour may increase exposure. Contagion hot-spots occur at the nexus of exposure and underlying susceptibility. The viral-host dynamics of infectious disease are changing. Now, as in past eras, societies are required to evolve and adapt to the new challenges presented by emerging infectious diseases in the modern world.

Calculating real-world travel routes instead of straight-line distance in the community response to out-of-hospital cardiac arrest

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In out-of-hospital cardiac arrest, straight-line distance estimates substantially underestimated actual travel distance for bystanders retrieving a nearby public-access AED and for volunteer first-responders travelling to the scene.

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Using real-world travel estimates changed the identity of the nearest public-access AED in more than a quarter of out-of-hospital cardiac arrests.

Background

Using straight-line distance to estimate the proximity of public-access Automated External Defibrillators (AEDs) or volunteer first-responders to potential out-of-hospital cardiac arrests (OHCAs) does not reflect real-world travel distance. The difference between estimates may be an important consideration for bystanders and first-responders responding to OHCAs and may potentially impact patient outcome.

Objectives

To explore how calculating real-world travel routes instead of using straight-line distance estimates might impact the community response to OHCA.

Methods

We mapped 4355 OHCA (01/04/2016-31/03/2017) and 2677 AEDs in London (UK), and 1263 OHCA (18/06/2017-17/06/2018) and 4704 AEDs in East Midlands (UK) using ArcGIS mapping software. We determined the distance from OHCAs to the nearest AED using straight-line estimates and real-world travel routes. We mapped locations of potential OHCAs (London: n = 9065, 20/09/2019-22/03/2020; East Midlands: n = 7637, 20/09/2019-17/03/2020) for which volunteer first-responders were alerted by the GoodSAM mobile-phone app, and calculated response distance using straight-line estimates and real-world travel routes. We created Receiver Operating Characteristic (ROC) curves and calculated the Area Under the Curve (AUC) to determine if travel distance predicted whether or not a responder accepted an alert.

Results

Real-world travel routes to the nearest AED were (median) 219 m longer (623 m vs 406 m) than straight-line estimates in London, and 211 m longer (568 m vs 357 m) in East Midlands. The identity of the nearest AED changed on 26% occasions in both areas when calculating real-world travel routes. GoodSAM responders’ real-world travel routes were (median) 222 m longer (601 m vs 379 m) in London, and 291 m longer (814 m vs 523 m) in East Midlands. AUC statistics for both areas demonstrated that neither straight-line nor real-world travel distance predicted whether or not a responder accepted an alert.

Conclusions

Calculating real-world travel routes increases the estimated travel distance and time for those responding to OHCAs. Calculating straight-line distance may overestimate the benefit of the community response to OHCA.

The effects of a leaflet-based intervention, 'Hypos can strike twice', on recurrent hypoglycaemic attendances by ambulance services: A non-randomised stepped wedge study

AIMS

We aimed to investigate the effect of an intervention in which ambulance personnel provided advice supported by a booklet-'Hypos can strike twice'-issued following a hypoglycaemic event to prevent future ambulance attendances.

METHODS

We used a non-randomised stepped wedge-controlled design. The intervention was introduced at different times (steps) in different areas (clusters) of operation within East Midlands Ambulance Service NHS Trust (EMAS). During the first step (T0), no clusters were exposed to the intervention, and during the last step (T3), all clusters were exposed. Data were analysed using a general linear mixed model (GLMM) and an interrupted-time series analysis (ITSA).

RESULTS

The study included 4825 patients (mean age 65.42 years, SD 19.42; 2,166 females) experiencing hypoglycaemic events attended by EMAS. GLMM indicated a reduction in the number of unsuccessful attendances (i.e., attendance followed by a repeat attendance) in the final step of the intervention when compared to the first (odds ratio OR: 0.50, 95%CI: 0.33-0.76, p = 0.001). ITSA indicated a significant decrease in repeat ambulance attendances for hypoglycaemia-relative to the pre-intervention trend (p = 0.008). Furthermore, the hypoglycaemia care bundle was delivered in 66% of attendances during the intervention period, demonstrating a significant level of practice change (p < 0.001).

CONCLUSION

The 'Hypos can strike twice' intervention had a positive effect on reducing numbers of repeat attendances for hypoglycaemia and in achieving the care bundle. The study supports the use of information booklets by ambulance clinicians to prevent future attendances for recurrent hypoglycaemic events.

OP07 On the effectiveness and costs of inhaled methoxyflurane versus usual analgesia for prehospital injury and trauma

Background

Acute pain is often inadequately treated in adults with traumatic injury. Inhaled methoxyflurane, newly licensed in Europe for this indication, has limited evidence of clinical effectiveness in the prehospital setting. We aimed to investigate clinical effectiveness and costs of methoxyflurane administered by ambulance staff compared with usual analgesic practice (UAP) for patients with trauma.

Methods

We used a non-randomised control group pragmatic design comparing methoxyflurane versus Entonox® and parenteral analgesics. Verbal numerical pain scores (VNPS) were gathered over time in adults with moderate to severe trauma pain attended by ambulance staff trained in administering and supplied with methoxyflurane. Comparator VNPS were obtained from database records of UAP in similar patients. Clinical efficacy was tested using an Ordered Probit panel regression model of pain linked by observational rules to VNPS. Scenario analyses were used to compare durations under analgesia spent in severe pain, and costs.

Results

Over 12 months, 96 trained paramedics and technicians prepared 510 doses of methoxyflurane for administration to 483 patients. 32 patients reported side-effects, 19 of whom discontinued early. 13 patients, 10 aged over 75 years, were nonadherent to inhaler use instructions.

Modelling results showed statistically significant clinical effectiveness of methoxyflurane over each comparator (all p-values<0.001). Methoxyflurane’s time to achieve maximum pain relief was significantly faster (all p-values<0.001): 26.4 mins (95%CI 25.0-27.8) versus Entonox® 44.4 (39.5-49.3); 26.5 (25.0-27.9) versus IV morphine sulfate 41.8 (38.9-44.7); 26.5 (25.1-28.0) versus IV paracetamol 40.8 (34.7-46.9).

Scenario analyses of durations spent in severe pain were significantly less for methoxyflurane to comparators. Benefits of methoxyflurane were achieved at higher cost to comparators.

Conclusions

Methoxyflurane reduced pain more rapidly and to a greater extent than Entonox® and more quickly than parenteral analgesics in adults with moderate or severe pain due to trauma attended by ambulance clinicians. Methoxyflurane provides a useful addition to prehospital analgesia.

01 The effects of a leaflet-based intervention, ‘hypos can strike twice’, on recurrent hypoglycaemic attendances by ambulance services: a non-randomised stepped wedge study

Background

Hypoglycaemia is a common complication of diabetes therapy needing prompt recognition and treatment. It often results in ambulance attendance incurring health services costs and patient morbidity. Patient education is important for maintaining glycaemic control and preventing recurrent hypoglycaemia. We aimed to investigate the effect of an intervention in which ambulance staff were trained to provide advice supported by a booklet – ‘Hypos can strike twice’- issued following a hypoglycaemic event to prevent future attendances.

Methods

We used a non-randomised stepped wedge-controlled design. The intervention was introduced at different times (steps) in different areas (clusters) of operation of East Midlands Ambulance Service NHS Trust (EMAS). During the first step (T0) no clusters were exposed to the intervention and during the last step (T3) all clusters were exposed. The main outcome was the number of unsuccessful ambulance attendances (i.e. attendances followed by a repeat attendance). Data were analysed using a general linear mixed model (GLMM) and an interrupted-time series analysis (ITSA).

Results

The study included 4825 patients (mean age= 65.42, SD=19.42; 2166 females) experiencing hypoglycaemic events attended by EMAS. GLMM indicated a reduction in the number of unsuccessful attendances in the final step of the intervention when compared to the first (OR: 0.50, 95%CI: 0.33-0.76, p=0.001). ITSA indicated a significant decrease in repeat ambulance attendances for hypoglycaemia – relative to the pre-intervention trend (p=0.008). The hypoglycaemia care bundle (i.e. blood glucose recorded before and after treatment for hypoglycaemia) was delivered in 66% of attendances during the intervention period, demonstrating a significant level of practice change (χ2=30.16, p<0.001).

Conclusions

The ‘Hypos can strike twice’ intervention had a positive effect on reducing numbers of repeat attendances for hypoglycaemia and in achieving the care bundle. The study supports the use of informative booklets by ambulance clinicians to prevent future attendances for recurrent hypoglycaemic events.

Call volume, triage outcomes, and protocols during the first wave of the COVID-19 pandemic in the United Kingdom: Results of a national survey

OBJECTIVES

During the first wave of the COVID-19 pandemic in the United Kingdom (UK), to describe volume and pattern of calls to emergency ambulance services, proportion of calls where an ambulance was dispatched, proportion conveyed to hospital, and features of triage used.

METHODS

Semistructured electronic survey of all UK ambulance services (n = 13) and a request for routine service data on weekly call volumes for 22 weeks (February 1-July 3, 2020). Questionnaires and data request were emailed to chief executives and research leads followed by email and telephone reminders. The routine data were analyzed using descriptive statistics, and questionnaire data using thematic analysis.

RESULTS

Completed questionnaires were received from 12 services. Call volume varied widely between services, with a UK peak at week 7 at 13.1% above baseline (service range -0.5% to +31.4%). All services ended the study period with a lower call volume than at baseline (service range -3.7% to -25.5%). Suspected COVID-19 calls across the UK totaled 604,146 (13.5% of all calls), with wide variation between services (service range 3.7% to 25.7%), and in service peaks of 11.4% to 44.5%. Ambulances were dispatched to 478,638 (79.2%) of these calls (service range 59.0% to 100.0%), with 262,547 (43.5%) resulting in conveyance to hospital (service range 32.0% to 53.9%). Triage models varied between services and over time. Two primary call triage systems were in use across the UK. There were a large number of products and arrangements used for secondary triage, with services using paramedics, nurses, and doctors to support decision making in the call center and on scene. Frequent changes to triage processes took place.

CONCLUSIONS

Call volumes were highly variable. Case mix and workload changed significantly as COVID-19 calls displaced other calls. Triage models and prehospital outcomes varied between services. We urgently need to understand safety and effectiveness of triage models to inform care during further waves and pandemics.

Mental health emergencies and COVID-19: the impact of 'lockdown' in the East Midlands of the UK

BACKGROUND

The most immediate response of the research community to COVID-19 has been a focus on understanding the effects, treatment and prevention of infection. Of equal and ongoing importance is elucidating the impact of mitigation measures, such as lockdown, on the well-being of societies. Research about mental health and lockdown in the UK has predominately involved large surveys that are likely to encounter self-selection bias. Further, self-reporting does not constitute a clinical judgement.

AIMS

To (a) compare the age, gender and ethnicity of patients experiencing mental health emergencies prior compared with during lockdown, (b) determine whether the nature of mental health emergencies has changed during compared with before lockdown, (c) explore the utility of emergency medical service data for identifying vulnerability to mental health emergencies in real time during a pandemic.

METHOD

A total of 32 401 clinical records of ambulance paramedics attending mental health emergencies in the East Midlands of the UK between 23 March and 31 July 2020 and the same period in 2019 were analysed using binary logistic regression.

RESULTS

People of younger age, male gender and South Asian and Black ethnicity are particularly vulnerable to acute mental health conditions during lockdown. Patients with acute cases of anxiety have increased during lockdown whereas suicide and intentional drug overdose have decreased.

CONCLUSIONS

Self-reported data may underrepresent the true impact of lockdown on male mental health and ethnic minority groups. Emergency medical data can be used to identify vulnerable communities in the context of the extraordinary circumstances surrounding the current pandemic, as well as under more ordinary circumstances.

Risk prediction models for out-of-hospital cardiac arrest outcomes in England

AIMS

The out-of-hospital cardiac arrest (OHCA) outcomes project is a national research registry. One of its aims is to explore sources of variation in OHCA survival outcomes. This study reports the development and validation of risk prediction models for return of spontaneous circulation (ROSC) at hospital handover and survival to hospital discharge.

METHODS AND RESULTS

The study included OHCA patients who were treated during 2014 and 2015 by emergency medical services (EMS) from seven English National Health Service ambulance services. The 2014 data were used to identify important variables and to develop the risk prediction models, which were validated using the 2015 data. Model prediction was measured by area under the curve (AUC), Hosmer-Lemeshow test, Cox calibration regression, and Brier score. All analyses were conducted using mixed-effects logistic regression models. Important factors included age, gender, witness/bystander cardiopulmonary resuscitation (CPR) combined, aetiology, and initial rhythm. Interaction effects between witness/bystander CPR with gender, aetiology and initial rhythm and between aetiology and initial rhythm were significant in both models. The survival model achieved better discrimination and overall accuracy compared with the ROSC model (AUC = 0.86 vs. 0.67, Brier score = 0.072 vs. 0.194, respectively). Calibration tests showed over- and under-estimation for the ROSC and survival models, respectively. A sensitivity analysis individually assessing Index of Multiple Deprivation scores and location in the final models substantially improved overall accuracy with inconsistent impact on discrimination.

CONCLUSION

Our risk prediction models identified and quantified important pre-EMS intervention factors determining survival outcomes in England. The survival model had excellent discrimination.

PP16 Modelling of patient outcomes after emergency treatment for out-of-hospital cardiac arrest by paramedics and community first responders

Background

Patient outcomes for out-of-hospital-cardiac-arrest (OHCA) should include shorter term response resulting from care delivered by first aiders (CFR) and emergency services as well as any longer term response achieved following handover into hospital care. We construct statistical models of: Return of Spontaneous Circulation while under emergency care (ROSC), and Discharge Alive from hospital (DA).

Methods

Data on 15,103 OHCA patients aged 4+weeks from East Midlands Ambulance Service NHS Trust were gathered across a 3 year period April 2014 – March 2017. Both outcomes were represented by binary variables (yes=1, no=0). Duration variables: waiting time (WT; time from 999 to emergency service arrival at the patient’s side), total treatment time (TOT; time from emergency service arrival to patient handover at hospital), time to ROSC (TtoR; time from emergency service arrival to first ROSC achieved). Statistical analyses were to be conducted on complete records (2825 patients) and involve fitting of a bivariate probit model to the joint outcome (ROSC, DA) and a probit model to the conditional outcome (DA|ROSC=1).

Results

CFR attendance had no statistically significant influence on either patient outcome.

Patient outcomes worsened as wait time (WT) increased, but was insignificant versus no effect.

Total treatment time (TOT) was significant; with positive influence on ROSC occurrence the longer that time period (estimate >0, p=0.036), but worsening the chance of longer term survival DA (estimate <0, p<0.001).

Time to ROSC (TtoR) was the key driver in the DA|ROSC=1 model (estimate <0, p<0.001), evidencing the better the chances of longer term survival DA the sooner ROSC is achieved.

Conclusions

Our Results show that OHCA patient outcomes depend crucially on the quality of clinical care provided by the emergency services. Next steps include the need to gather granular data evidencing the pre-hospital care that is administered to patients by paramedics and community first responders.

Data quality and 30-day survival for out-of-hospital cardiac arrest in the UK out-of-hospital cardiac arrest registry: a data linkage study

OBJECTIVES

The Out-of-Hospital Cardiac Arrest Outcomes (OHCAO) project aims to understand the epidemiology and outcomes of out-of-hospital cardiac arrest (OHCA) across the UK. This data linkage study is a subproject of OHCAO. The aim was to establish the feasibility of linking OHCAO data to National Health Service (NHS) patient demographic data and Office for National Statistics (ONS) date of death data held on the NHS Personal Demographics Service (PDS) database to improve OHCAO demographic data quality and enable analysis of 30-day survival from OHCA.

DESIGN AND SETTING

Data were collected from 1 January 2014 to 31 December 2014 as part of a prospective, observational study of OHCA attended by 10 English NHS Ambulance Services. 28 729 OHCA cases had resuscitation attempted by Emergency Medical Services and were included in the study. Data linkage was carried out using a data linkage service provided by NHS Digital, a national provider of health-related data. To assess data linkage feasibility a random sample of 3120 cases was selected. The sample was securely transferred to NHS Digital to be matched using OHCAO patient demographic data to return previously missing demographic data and provide ONS date of death data.

RESULTS

A total of 2513 (80.5%) OHCAO cases were matched to patients in the NHS PDS database. Using the linkage process, missing demographic data were retrieved for 1636 (72.7%) out of 2249 OHCAO cases that had previously incomplete demographic data. Returned ONS date of death data allowed analysis of 30-day survival status. The results showed a 30-day survival rate of 9.3%, reducing unknown survival status from 46.1% to 8.5%.

CONCLUSIONS

In this sample, data linkage between the OHCAO registry and NHS PDS database was shown to be feasible, improving demographic data quality and allowing analysis of 30-day survival status.