Factors affecting the ambulance response times of trauma incidents in Singapore

A study of prehospital EMS response time and influencing factors in the main urban area of Chongqing, China

Shortening the prehospital emergency medical service (EMS) response time is crucial for saving lives and lowering mortality and disability rates in patients with sudden illnesses. Descriptive analyses of prehospital EMS response time and each component were conducted separately using ambulance trip data from the 120 Dispatch Command Centre in the main urban area of Chongqing in 2021, and then, logistic regression analyses were used to explore the influencing factors. The median prehospital EMS response time in the main urban area of Chongqing was 14.52 min and the mean was 16.14 min. A 44.89% of prehospital EMS response time exceeded 15 min. Response time was more likely to surpass this threshold during peak hours and in high population density areas. Conversely, lower probabilities exceeding 15 min were observed during the night shift, summer, and autumn seasons, and areas with a high density of emergency station. 33.28% of preparation time was >3 min, with the night shift and high population density areas more likely to be >3 min, while for the summer and autumn seasons, high Gross National Product (GDP) per capita areas had a lower likelihood of having preparation time >3 min. 45.52% of travel time was >11 min, with peak hours, summer and autumn, and high GDP per capita areas more likely to have had a travel time >11 min, while night shift and high emergency station density areas had a lower likelihood of travel time >11 min. The primary factors influencing prehospital EMS response time were shifts, traffic scenarios, seasons, GDP per capita, emergency station density, and population density. Relevant departments can devise effective interventions to reduce response time through resource allocation and department coordination, staff training and work arrangement optimisation, as well as public participation and education, thereby enhancing the efficiency of prehospital emergency medical services.

Incidence and predictors of mortality among road traffic accident victims admitted to hospitals at Hawassa city, Ethiopia

BACKGROUND

Globally, road traffic accidents are the eighth-leading cause of death for all age groups. The estimated number of road traffic deaths in low income countries was more than three times as high as in high-income countries. Africa had the highest rate of fatalities attributed to road traffic accidents. Ethiopia has the highest number of road traffic fatalities among Sub-Saharan African countries. The main objective of this study was to determine the incidence and predictors of mortality among road traffic victims admitted to hospitals in Hawassa City.

METHODS

A facility-based retrospective cohort study was conducted using secondary data from hospital records. A total of 398 road traffic accident victims admitted to selected hospitals in Hawassa city from January 2019 to December 2021 participated in the study. Data were analyzed using STATA version 14.1. The Cox regression model was used to determine the predictors of mortality. A hazard ratio with a 95% confidence interval and a cut-off value of P<0.05 was used to declare the risk and statistical significance, respectively.

RESULT

The incidence rate of mortality for road traffic accident victims was 7.34 per 10,000 person-hours. The predictors of mortality were the value of GCS at admission <8 (aHR = 5.86; 95% CI: 2.00-17.19), GCS at admission 9-12 (aHR = 3.27; 95% CI: 1.28-8.40), the value of SBP at admission ≤89mmHg (aHR = 4.41; 95% CI: 2.22-8.77), admission to the ICU (aHR = 3.89; 95% CI: 1.83-8.28) and complications (aHR = 5.48; 95% CI: 2.74-10.01).

CONCLUSION

The incidence of mortality among road traffic victims admitted to hospitals in Hawassa city was high. Thus, thorough follow-up and intensive management should be given to victims with critical health conditions.

Emergency services utilization in Jakarta (Indonesia): a cross-sectional study of patients attending hospital emergency departments

BACKGROUND

Pre-hospital and emergency services in Indonesia are still developing. Despite recent improvements in the Indonesian healthcare system, issues with the provision of pre-hospital and emergency services persist. The demand for pre-hospital and emergency services has not been the subject of previous research and, therefore, has not been fully understood. Our research explored the utilization of emergency medical services by patients attending hospital emergency departments in Jakarta, Indonesia.

METHODS

The study used a cross-sectional survey design involving five general hospitals (four government-funded and one private). Each patient's demographic profile, medical conditions, time to treatment, and mode of transport to reach the hospital were analysed using descriptive statistics.

RESULTS

A total of 1964 (62%) patients were surveyed. The median age of patients was 44 years with an interquartile range (IQR) of 26 to 58 years. Life-threatening conditions such as trauma and cardiovascular disease were found in 8.6 and 6.6% of patients, respectively. The majority of patients with trauma travelled to the hospital using a motorcycle or car (59.8%). An ambulance was used by only 9.3% of all patients and 38% of patients reported that they were not aware of the availability of ambulances. Ambulance response time was longer as compared to other modes of transportation (median: 24 minutes and IQR: 12 to 54 minutes). The longest time to treatment was experienced by patients with neurological disease, with a median time of 120 minutes (IQR: 78 to 270 minutes). Patients who used ambulances incurred higher costs as compared to those patients who did not use ambulances.

CONCLUSION

The low utilization of emergency ambulances in Jakarta could be contributed to patients' lack of awareness of medical symptoms and the existence of ambulance services, and patients' disinclination to use ambulances due to high costs and long response times. The emergency ambulance services can be improved by increasing population awareness on symptoms that warrant the use of ambulances and reducing the cost burden related to ambulance use.

Exploration of the police response time to motor-vehicle crashes in Pennsylvania, USA

INTRODUCTION

After roadway crashes occur, the quick emergency response is essential for minimizing tolls and economic losses. Many studies have analyzed the post-crash emergency medical services response time, but few ones have explored the post-crash police response time. However, the presence of police is the precondition for other agencies to perform their duties safely and smoothly.

METHOD

With Pennsylvania crash data from 2008 to 2017, this study gives an assessment of the post-crash police response time in Pennsylvania.

RESULTS

First, we demonstrate that police response time is highly correlated to crash consequences: the longer police response time is positively associated with more fatalities at both individual level and county level. Then, for fatal crashes, a negative binomial model with the police agency-level random effects is built to identify the significant factors influencing the police response time. The results indicate that day of week, illumination, weather, area, roadway type, and roadway location could significantly affect the police response time. Police respond much slower to fatal crashes occurring in rural areas, mid-blocks, turnpikes, adverse weather, on weekends, and at nighttime without streetlights. Police response time shows a decreasing trend since 2016 and varies a lot by police agencies. It is found that many police agencies affiliated to the Pennsylvania State Police, which oversees statewide law enforcement on all interstate and state highways, respond slower than other police agencies. Practical Applications: These findings are expected to provide some new insights for Pennsylvania police agencies to improve their response mechanisms to roadway crashes.

Metaheuristics in the decentralization of SAMU bases using simulation in northeastern Brazil

BACKGROUND AND OBJECTIVE

The growth of the urban population exerts considerable pressure on municipalities' public managers to focus their attention on providing emergency medical care that meets the growing demand for emergency pre-hospital medical care. Currently, there are a significant number of traffic accidents and other serious occurrences, such as heart attacks, drownings, epidemics, fires and disasters (floods, landslides, earthquakes) that demand a prompt and seamless response from pre-hospital medical care. As a result of such scenario, the present article endeavours to apply a dual-coverage mathematical model (DSM-Double Standard Model) to define the optimal location of the Emergency Medical Service (SAMU) decentralized dispatch bases in Natal/RN and conduct a simulation study to evaluate the displacement of ambulances between such bases.

METHODS

The methodological course that was followed by this research constitutes of 12 steps. The location of decentralized bases for sending emergency ambulances was established using the DSM model and the simulation model was performed using the FlexSim© software version 2018 evaluating base coverage in relation to the total number of calls by demand points for different scenarios.

RESULTS

The results obtained throughout the research demonstrated the feasibility of redefining the decentralized bases of SAMU/Natal ambulances as a strategy to reduce response time and guarantee compliance with performance parameters established by international organizations (the World Health Organization, for instance, establishes the time of 8 minutes for emergency medical service calls response). The simulation study showed a significant reduction in response time, by up to 60% in some cases.

CONCLUSION

The proposition of new locations for the decentralized dispatch bases of the SAMU/Natal can provide an overall significant reduction on the ambulance response time, so as to contribute to expedite the initiation of treatment of patients, if necessary, sent to hospitals.

Mobile Ambulatory Application Asafny and Traditional Phone Request 997: A Comparative Cross-Sectional Study

Purpose

This study aimed to determine whether there was a time difference between the ambulatory application Asafny and traditional type 997 in reaching people in need and interacting appropriately.

Materials and Methods

This study was conducted using retrospective cross-sectional study. A total of 2120 ambulance requests was extracted from Saudi Red Crescent Authority servers in Eastern Province, Kingdom of Saudi Arabia. The requests were extracted between 2017 and 2019.

Results

There were no significant differences between the two methods of request. In 2019, the shortest times for all phases of requests were recorded. "Ordinary patient" was the most common cause for requests.

Conclusion

Over the years, efforts by the Saudi Red Crescent Authority facilitated improvements in ambulatory services by adapting new technology and services. This has helped reduce times for all phases of emergency requests.

Strengthening the Capacity of Emergency Medical Services in Low and Middle Income Countries using Dispatcher-Coordinated Taxis

International standards recommend provision of 1 ambulance for every 50,000 people to fulfil demand for transporting patients to definitive care facilities in Low and Middle Income Countries (LMICs). Governments' consistent attempt to build capacity of emergency medical services (EMS) in LMICs has been financially demanding. This study is an attempt to assess the feasibility of capacity building of existing EMS in Delhi, India by using taxis as an alternative mode of transport for emergency transportation of road traffic crash victims to enable improvement in response time for road traffic crashes where time criticality is deemed important. Performance of the proposed system is evaluated based on response time, coverage and distance. The system models the performance and quantifies the taxi - ambulance configuration for achieving EMS performance within international standards.

Effects of hourly precipitation and temperature on ambulance response time

BACKGROUND

Longer ambulance response time (ART) delaying treatment would worsen conditions of seriously ill or injured patients, but limited evidence is available on the effects of weather factors on ART. This study aims to assess precipitation- and temperature-ART associations and their potential lagged effects using a novel modeling strategy.

METHODS

Based on 779,156 emergency records during 2010-2016 from the whole population in Shenzhen, China, we creatively combined quantile regression with distributed-lag nonlinear models to examine the non-linear and lagged effects of hourly precipitation and temperature on ART at the 50th and 90th percentiles.

RESULTS

A linear precipitation-ART association with a delay of 9.01 (95%CI, 7.82-10.20) seconds at median ART for a 1 mm increase in hourly precipitation, and the effects lasted for 5 h with the greatest effect at the current hour. A two linear thresholds temperature-ART association revealed 1 °C decrease below 19 °C caused 1.68 (95%CI, 0.92-2.44) seconds delay in total ART over lag 0-7 h, and 1 °C increase above 24 °C caused 2.44 (95%CI, 1.55-3.33) seconds delay. The hourly call volumes exceeding 54 calls caused 8.79 (95%CI, 8.71-8.86) seconds delay in total ART for 1 more call, but not affected the effects of weather factors. The internal ART suffered more from the hourly call volumes, while the external ART suffered more from precipitation and temperature. The effects were apparently greater on ART at the 90th percentile than median.

CONCLUSIONS

Precipitation and temperature are independent risk factors for ambulance services performance, and their lagged effects are notable. The external ART and patients with long ART are vulnerable. More attention should be paid to weather and ART, and these findings may have implications for effective policies to reduce ART to protect public health.

Identifying characteristics that impact motor carrier safety using Bayesian networks

PROBLEM STATEMENT

In the U.S., a safety rating is assigned to each motor carrier based on data obtained from the Motor Carrier Management Information System (MCMIS) and an on-site investigation. While researchers have identified variables associated with the safety ratings, the specific direction of the relationships are not necessarily clear.

OBJECTIVE

The objective of this study is to identify those relationships involved in the safety ratings of interstate motor carriers, the largest users of the U.S. transportation network.

METHOD

Bayesian networks are used to learn these relationships from data obtained from MCMIS for a 6-year period (2007-2012).

RESULTS

Our study shows that safety rating assignment is a complex process with only a subset of the variables having statistically significant relationship with safety rating. They include driver out-of-service violations, weight violations, traffic violations, fleet size, total employed drivers, and passenger & general carrier indicators.

APPLICATION

The findings have both immediate implications and long term benefits. The immediate implications relate to better identification of unsafe motor carriers, and the long term benefits pertain to policies and crash countermeasures that can enhance carrier safety.

Factors Influencing the Emergency Medical Service Response Time for Cardiovascular Disease in Guangzhou, China

While emergency medical service (EMS) response time (ERT) is a major factor associated with the survival of patients with cardiovascular disease (CVD), relatively few studies have explored the factors associated with ERT. This study aimed to assess the current status of ERT and to identify the factors affecting ERT in patients with CVD in China. Between January 1, 2011 and December 31, 2015, EMS responses to CVD incidents in Guangzhou, China, were examined. The primary outcome was ERT, defined as the time from receipt of an emergency call to the arrival of paramedics on the scene. Factors associated with ERT were evaluated by multivariable logistic regression. A total of 44 383 CVD incidents were analysed. The median ERT was 12.58 min (interquartile range=9.98-15.67). Among the risk factors, distance (OR=13.73, 95% CI=11.76-16.04), level of hospital (OR=1.57, 95% CI=1.40-1.75), and site of the incident (OR=1.53, 95% CI=1.38-1.69) were the top three significant factors affecting the ERT. Our results suggest that greater attention should be given to factors affecting the ERT. It is essential to make continuous efforts to promote the development of effective interventions to reduce the response time.

Weather and Temporal Factors Associated with Use of Emergency Medical Services

Background: Fluctuations in emergency medical services (EMS) responses can have a substantial impact on the ability of agencies to meet resource needs within an EMS system. We aimed to identify weather characteristics as potentially predictable factors associated with EMS responses. Methods: We reviewed hourly counts of scene responses documented by 24 EMS agencies in Western Pennsylvania from January 1, 2014 to December 31, 2017 and compared rates of responses to weather characteristics. Responses to counties nonadjacent to the studied weather reporting station and interfacility/scheduled transports were excluded. We identified the mean temperature, meters visibility, dew point, wind speed, total millimeters of precipitation, and presence of rain or snow in 6-hour windows prior to dispatch, in addition to temporal factors of time of day and weekend vs. weekday. Analysis was performed using multivariable linear regression of a negative binomial distribution, reporting incidence rate ratios (IRR) with 95% confidence intervals (CI). Secondary analyses were performed for transports to the hospital and cases involving transports for traumatic complaints and pediatric patients (age <18 years). Results: We included 529,058 responses (54.8% female, mean age 57.2 ± SD 24.7 years). In our multivariable model, responses were associated with (IRR, 95% CI) rain (1.10, 1.08-1.11) snow (1.07, 1.05-1.09), and both rain and snow (1.15, 1.11-1.19). A lower incidence of responses occurred on weekends (0.84, 0.83-0.85) and at night (0.62, 0.61-0.62). Increasing temperature in 5 °C increments was associated with an increase in responses across seasons with an effect that varied between 1.16 (1.15-1.17) in winter to 1.31 (1.28-1.33) in summer. Windy weather was associated with increased responses from light breeze (1.10, 1.09-1.11) to fresh breeze or greater (1.23, 1.16-1.30). Transports occurred in a similar pattern to responses. Trauma transports (n = 64,235) occurred more during weekends (1.04, 1.02-1.06). Pediatric transports (n = 21,880) were not significantly associated with precipitation or season. Conclusion: EMS responses increased with rising temperature and following rain and snow. These findings may assist in planning by EMS agencies and emergency departments to identify periods of greatest resource utilization.

Response time in the emergency services. Systematic review

The growth of the urban population raises concern about municipal public managers in the sense of providing emergency medical services (EMS) that are aligned with the needs of prehospital emergency medical care demanded by the population. The literature review aims at presenting the response time of emergency medical services in several parts of the world and discussing some factors that interfere in the result of this indicator such as GDP (Gross Domestic Product) percentage spent on health and life expectancy of countries. The study will also show that in some of the consulted articles, authors suggest to EMS recommendations for decreasing the response time using simulations, heuristics and metaheuristics. Response time is a basic indicator of emergency medical services, in such a way that researchers use the descriptive statistics to evaluate this parameter. Europe and the USA outstand in the publication of studies that present this information. Some articles use stochastic and mathematical methods to suggest models that simulate scenarios of response time reduction and suggest such proposals to the local EMS. Countries in which the response time was identified have a high index of human development and life expectancy between 74.7 and 83.7 years.

Medical facilities in the neighborhood and incidence of sudden cardiac arrest

BACKGROUND

Medical establishments in the neighborhood, such as pharmacies and primary care clinics, may play a role in improving access to preventive care and treatment and could explain previously reported neighborhood variations in sudden cardiac arrest (SCA) incidence and survival.

METHODS

The Cardiac Arrest Blood Study Repository is a population-based repository of data from adult cardiac arrest patients and population-based controls residing in King County, Washington. We examined the association between the availability of medical facilities near home with SCA risk, using adult (age 18-80) Seattle residents experiencing cardiac arrest (n = 446) and matched controls (n = 208) without a history of heart disease. We also analyzed the association of major medical centers near the event location with emergency medical service (EMS) response time and survival among adult cases (age 18+) presenting with ventricular fibrillation from throughout King County (n = 1537). The number of medical facilities per census tract was determined by geocoding business locations from the National Establishment Time-Series longitudinal database 1990-2010.

RESULTS

More pharmacies in the home census tract was unexpectedly associated with higher odds of SCA (OR:1.28, 95% CI: 1.03, 1.59), and similar associations were observed for other medical facility types. The presence of a major medical center in the event census tract was associated with a faster EMS response time (-53 s, 95% CI: -84, -22), but not with short-term survival.

CONCLUSIONS

We did not observe a protective association between medical facilities in the home census tract and SCA risk, orbetween major medical centers in the event census tract and survival.

Significant acceleration of emergency response using smartphone geolocation data and a worldwide emergency call support system

Importance

When patients are disorientated or experience language barriers, it is impossible to activate the emergency response system. In these cases, the delay for receiving appropriate help can extend to several hours.

Objectives

A worldwide emergency call support system (ECSS), including geolocation of modern smartphones (GPS, WLAN and LBS), was established referring to E911 and eCall systems. The system was tested for relevance in quickly forwarding abroad emergency calls to emergency medical services (EMS).

Design

To verify that geolocation data from smartphones are exact enough to be used for emergency cases, the accuracy of GPS (global positioning system), Wi-Fi (wireless LAN network) and LBS (location based system) was tested in eleven different countries and compared to actual location. The main objective was analyzed by simulation of emergencies in different countries. The time delay in receiving help in unsuccessful emergency call cases by using the worldwide emergency call support system (ECSS) was measured.

Results

GPS is the gold standard to locate patients with an average accuracy of 2.0 ± 3.3 m. Wi-Fi can be used within buildings with an accuracy of 7.0 ± 24.1 m. Using ECSS, the emergency call leads to a successful activation of EMS in 22.8 ± 10.8 min (Median 21 min). The use of a simple app with one button to touch did never cause any delay.

Conclusions and relevance

The worldwide emergency call support system (ECSS) significantly improves the emergency response in cases of disorientated patients or language barriers. Under circumstances without ECSS, help can be delayed by 2 or more hours and might have relevant lifesaving effects. This is the first time that Wi-Fi geolocation could prove to be a useful improvement in emergencies to enhance GPS, especially within or close to buildings.

Simulation-based decision support framework for dynamic ambulance redeployment in Singapore

OBJECTIVE

Dynamic ambulance redeployment policies tend to introduce much more flexibilities in improving ambulance resource allocation by capitalizing on the definite geospatial-temporal variations in ambulance demand patterns over the time-of-the-day and day-of-the-week effects. A novel modelling framework based on the Approximate Dynamic Programming (ADP) approach leveraging on a Discrete Events Simulation (DES) model for dynamic ambulance redeployment in Singapore is proposed in this paper.

METHODS

The study was based on the Singapore's national Emergency Medical Services (EMS) system. Based on a dataset comprising 216,973 valid incidents over a continuous two-years study period from 1 January 2011-31 December 2012, a DES model for the EMS system was developed. An ADP model based on linear value function approximations was then evaluated using the DES model via the temporal difference (TD) learning family of algorithms. The objective of the ADP model is to derive approximate optimal dynamic redeployment policies based on the primary outcome of ambulance coverage.

RESULTS

Considering an 8min response time threshold, an estimated 5% reduction in the proportion of calls that cannot be reached within the threshold (equivalent to approximately 8000 dispatches) was observed from the computational experiments. The study also revealed that the redeployment policies which are restricted within the same operational division could potentially result in a more promising response time performance. Furthermore, the best policy involved the combination of redeploying ambulances whenever they are released from service and that of relocating ambulances that are idle in bases.

CONCLUSION

This study demonstrated the successful application of an approximate modelling framework based on ADP that leverages upon a detailed DES model of the Singapore's EMS system to generate approximate optimal dynamic redeployment plans. Various policies and scenarios relevant to the Singapore EMS system were evaluated.