|Year : 2016 | Volume
| Issue : 1 | Page : 33-38
Ambulance response time to cardiac emergencies in Riyadh
Khalid Alnemer1, Khalid I Al-Qumaizi2, Ahmed Alnemer1, Ammar Alsayegh3, Alwaleed Alqahtani3, Yasser Alrefaie3, Mohammed Alkhalifa3, Ahmed Alhariri4
1 Department of Internal Medicine, Al-Imam Muhammad Ibn Saud Islamic University (Imsiu), School of Medicine, Riyadh, Saudia Arabia
2 Department of Family Medicine, Al-Imam Muhammad Ibn Saud Islamic University (Imsiu), School of Medicine, Riyadh, Saudia Arabia
3 Final Year Medical Student, Al-Imam Muhammad Ibn Saud Islamic University (Imsiu), School of Medicine, Riyadh, Saudia Arabia
4 Department of Medical Affairs, Saudi Red Crescent, Main Office, Riyadh, Saudia Arabia
|Date of Submission||27-Mar-2016|
|Date of Acceptance||21-May-2016|
|Date of Web Publication||7-Oct-2016|
Dr. Khalid Alnemer
School of Medicine, Al-Imam Muhammad Ibn Saud Islamic University, P. O. Box: 7544, Riyadh 13317-4233
Source of Support: None, Conflict of Interest: None
Background: Ambulance response time (ART) plays a significant role in patient survival, especially in cardiac emergencies; qualifying as the crucial factor to measure the quality of prehospital emergency care. Thus, this retrospective, cross-sectional study aimed to measure the ART to public cardiac emergencies and to analyze its association with patient survival in Riyadh.
Methods: Records of cardiac emergency medical services from the Saudi Red Crescent Authority for 1 year (January 1, 2013–December 31, 2013) in Riyadh were requisitioned. ART was calculated for 18 stations across Riyadh and assessed for confounding factors such as time (day of the week and time of the day), age, gender, and location of the incident.
Results: The mean ART was approximately 13 min, with a trend toward prolongation during working hours on weekdays. ART and survival were unaffected by gender and location of the incident but was confounded by the age of the patient (P = 0.001).
Conclusions/Recommendations: ART was much longer than the defined international standard of 8 min and comparable to other regions of the world. We recommend the use of motorcycles to transport paramedics to the emergency site, air ambulance, and dedicated ambulance lanes to reduce ART.
Keywords: Age, ambulance response time, cardiac emergencies, patient survival, Riyadh
|How to cite this article:|
Alnemer K, Al-Qumaizi KI, Alnemer A, Alsayegh A, Alqahtani A, Alrefaie Y, Alkhalifa M, Alhariri A. Ambulance response time to cardiac emergencies in Riyadh. Imam J Appl Sci 2016;1:33-8
|How to cite this URL:|
Alnemer K, Al-Qumaizi KI, Alnemer A, Alsayegh A, Alqahtani A, Alrefaie Y, Alkhalifa M, Alhariri A. Ambulance response time to cardiac emergencies in Riyadh. Imam J Appl Sci [serial online] 2016 [cited 2019 Nov 12];1:33-8. Available from: http://www.e-ijas.org/text.asp?2016/1/1/33/191991
| Introduction|| |
Early and effective delivery of emergency medical services (EMS) is essential in the present times due to the increasing prevalence of cardiac, cerebrovascular, and other acute medical conditions.,
The main objective of the EMS system is effective, consistent, and immediate medical care to seriously ill or injured patients and the rapid conveyance of patients to advanced resuscitation and lifesaving care. EMS is especially crucial for patients with out-of-hospital cardiac arrest.
The International Standards Organization has thus adopted response times as a key performance indicator of emergency services, providing a comparable, and verifiable measure of EMS performance across diverse cities.
The most widely accepted and tested tool to assess the quality of EMS is the interval between call receipt and arrival on scene, i.e., ambulance response time (ART), especially for cardiac emergencies., Results from numerous studies have shown a positive correlation and significant association between reduced ART and improved patient survival in cardiac emergencies.,, This has led to a creation of a “gold standard” response time (set at 8 min for cardiac emergencies  that has been shown to improve patient survival in cardiac emergencies. A great amount of effort has been made worldwide to meet this standard.,,,
The World Health Organization reported that cardiovascular disease (CVD) was the leading cause of deaths worldwide. Saudi Arabia has reported the highest number of CVD deaths and about half of the CVD-deaths occur in the prehospital setting. The Saudi Red Cross Authority (SRCA) is the only agency that manages the EMS in Saudi Arabia. In addition, a survey has shown that there is low reliance on EMS in Saudi Arabia.
Only one study was conducted in Riyadh in 2002 reporting an ART of approximately 10 min. Since then, no further efforts have been made to study ART and to determine whether there were any improvements. Thus, this retrospective cross-sectional study was conducted to measure the ART to public cardiac emergencies and to analyze its association with patient survival in Riyadh.
Studies have been conducted to examine the EMS worldwide, and the following response times have been observed for the various countries:
| Methods|| |
This retrospective study was based on the EMS system of Riyadh in Saudi Arabia. Riyadh is the capital and largest city of Saudi Arabia, with a population of close to 5.5 million people.
Saudi Arabia's EMS system is managed by SRCA, with approximately 165 ambulance stations in the country, each with two ambulances. The EMS team comprises of emergency physicians with expertise in EMS, paramedics, and ambulance employees. The levels of services available constitute three categories; basic life support, advanced life support, and care by healthcare professionals working in the ambulances. Most of the exigencies are managed by paramedics, including technicians, and the driver of the ambulance. A paramedic is a trained health professional who is the first responder to the patient in medical emergency. The paramedics provide out of hospital medical assessment, treatment, and care at varying levels.
Saudi's EMS system relies on the national “997” emergency hotline with round-the-clock operations which responds to medical, fire-related, and other civil emergencies. During the study, the fleet of ambulances was distributed over a network of 18 stations. On ambulance activation, the EMS center will deploy the nearest available ambulance to the incident scene. At the incident scene, patients are stabilized, given emergency medical treatment, and assigned a status: 1-alive, 2-alive, given CPR, 3-dead, 4-alive, conveyance not required, 5-dead, conveyance not required, and 6-not available. Following this, the patient was handed over to the hospital's emergency department.
The SRCA collects data on EMS requests and ambulance arrival times at the accident scene. Each emergency incident has its own implications (accident, fire, injury, etc.). This was a retrospective cross-sectional study based on the cardiac EMS dataset provided by SRCA for 1 year (January 1, 2013–December 31, 2013) in Riyadh. Details of noncardiac EMS were excluded from this study. The data were made anonymous by blotting out the caller name, phone number, and any form of identification obtained at the scene. Approval was obtained from Institutional Review Board of SRCA before study initiation.
The data collected from the patient records included:
- Patient demographics (age, gender, address), location during emergency
- Ambulance station name and number
- Vital signs (blood pressure, pulse rate)
- Emergency procedure administered (defibrillation, cardiopulmonary resuscitation)
- Date and time of call to 997, time of ambulance arrival at scene, time from ambulance received command to go to the scene, time of ambulance arrival to hospital, and survival status at hospital (dead, alive).
All records were reviewed by a Consultant Cardiologist to ensure only cardiac emergencies were included based on the Utstein template for out-of-hospital cardiac arrest.
The time interval between the call being received and the arrival of the ambulance on the scene (ART) was determined for each case, along with the effect on survival.
The effect of day of the week, time of the day, location of the emergency, gender and age of the patient on ART was also determined.
For the purpose of this study, “working days” were defined as Saturday to Wednesday, “weekends” were defined as Thursday/Friday until the Saudi government has changed weekend to Friday/Saturday during the data collection; which was adopted as such.
Furthermore, “working hours” were defined as 8:00 AM to 5:00 PM, and “late hours” were defined as 5:01 PM to 7:59 AM.
Data management was performed using Microsoft Excel (Excel 2007, Microsoft Corp.) and statistical analysis was carried out using the Statistical Package for Social Sciences version 17.0 (SPSS Inc., Chicago, IL, USA). Descriptive statistics was used to summarize the characteristics of the patients and other risk factors. Frequency, proportions, and percentages were calculated for qualitative data to calculate odds ratios and apply Chi-square test for statistical significance. Means were compared via a Student's t-test and analysis of variance. P < 0.05 was set for statistical significance.
| Results|| |
The overall sample consisted of 1406 emergency calls attended by 18 SRCA stations, over a 12-month period in Riyadh. The patients were assessed by an EMS expert at the respective hospitals.
To further derive data with the highest quality and information content, relatively incomplete data were excluded from the study, 273 calls with missing or inconsistent information were excluded from this study. Characteristics of the excluded data were missing or inconsistent timestamps (213) or duplicate entries (60). Remaining 1133 calls were analyzed. The expected travel time is a key factor in the dispatch decisions of ambulances. Typically, the nearest available ambulance was dispatched.
Ambulance response time and time
The overall mean ART value was found to be 13.21 ± 7.94 min (95% confidence interval [CI]: 12.74–13.69). [Table 1] shows that the day of the week had a trend towards prolongation of ART during weekdays. A similar effect was seen with time of the day, the mean ART being prolonged during office hours than late hours. There was a trend towards prolongation of ART for the patients that died in comparison with the live patients. However, this was not significant (P < 0.380) [Table 1]].
Ambulance response time and geographic location
The location of the emergency showed marked variation in the ART, as shown in [Table 2].
|Table 2: Ambulance response time by location and correlation with patient survival|
Click here to view
Most cardiac emergency calls were received by the Al Areej station (153 calls), closely followed by Al Oruba (152 calls). There was a marked variation in ART time across the centers, ranging from 9 to 15 min, with a mean of 12.9 min.
Ambulance response time and survival
Of the total 1133 patients, 16 patients died: 13 patients died on scene, and 3 patients died during transport to the hospital. The reasons for deaths are summarized in [Table 3].
The highest number of deaths (6 [3.9%]) were reported from the Al Oruba station. Survival rates were unaffected by all variables studied, even in those cases where the ART was at or below the set standard of 8 min [Table 3].
The sample was divided into three groups, namely, ART (0–8 min), ART (9–16 min), and ART >16 min for correlation with survival [Table 4].
There was no correlation between gender and survival. However, age of the patients was a confounding factor for ART (P = 0.001).
| Discussion|| |
This was a retrospective, cross-sectional study conducted to assess current ART in Riyadh, its association with patient survival in cardiac emergencies and whether other extrinsic factors such as day of the week or time of the day, had any effect on ART.
Time factor is most important for medical emergency. The overall mean ART value in our study was found to be 13.21 ± 7.94 min (95% CI: 12.74–13.69) versus an ART of 10.23 min (SD 5.66 min) in an EMS study conducted in Riyadh in 2002. A recent cross-sectional survey conducted in Jeddah revealed that of the patients who used EMS, most common scene time was 15 min.
With an average ART of ~13 min and many outliers on the right side of the distribution curve, the 8-minute response time that is believed to be so crucial for increased survival rates, is not being met in this study in Riyadh. This is disappointing since some international studies on ART for noncardiac emergencies (including noncritical general emergencies), showed ART well within the required 8 min interval.,, There has been no detectable improvement in ART since the study in 2002 reported ART of 10.23 min.
The most method of ambulance dispatch is the closest (geographically) available unit. Dispatching the closest ambulance to the site reduces the response time of the current call; however, it may increase the response time of the next incoming calls.
In this study, both sample size and study design were comparable to most other studies, as were the number of ambulance stations studied.,
This study found no correlation between ART and gender of the patients, in agreement with the Singapore ART study. However, ART was confounded by age of the patient, possibly because there was a higher number of elderly patients (>65 years) in this study. The elderly population requires increased care with over 80% of the population having at least 1 chronic illness and other comorbidities.
This can be also attributed to the increased traffic in the region. Severe traffic congestion and road safety issues caused by population growth and increased economic activity has made transport in and around Riyadh time consuming, affecting response to medical emergencies. In addition, vehicles are not allowed to enter highways at some entrances at peak times, thus defeating the purpose of having highways, which are supposed to reduce congestion.
Despite a wide range of transport services, issues such as parking, congested corridors, poorly functioning traffic signals to traffic safety and behavioral issues persist. In addition, the vertical response times (from the need to climb stairs and/or take elevators) needed for the EMS team to reach the patient can further contribute to the patient access delays. Other confounders such as weather and the location of incident, as also noted to affect ART in Singapore study.
Although the recommended ART is 8 min in various studies, a relation between increased survival rate and ART was found more often in those studies which had response times of <6 min.,,,,,,, Since none of the stations in this study had a mean ART below 8 min, we could not confirm whether this would indeed be the case.
In Canada, the ART was 9 min a little above the standard of 8 min, owing to uneven service across different regions and provinces across the country. In China, the ART was 5–10 min, owing to the lack of standardization for prehospital emergency care personnel, emergency department combined with prehospital emergency care, and lack of significant prehospital emergency care in rural areas. In Germany, the ART was 10–15 min due to lack of homogenous practices in emergency care. In Lithuania, there was a lack of standardization in emergency service resulting in an urban ART of 15 min. In South Africa, ART of 15 min in urban areas was attributed to lack of funds and equity distribution and too many patients. In Taiwan, the ART was well within the standard ART. In the UK, the lag in response it attributed to remote location of emergency and in the US, response time delay is attributed to remote environments and times of high demand. In the US, the lag in response time is due paramedics relaying findings of electrocardiography to the receiving hospital.
Intervention such as defibrillation determines survival from cardiac arrest, thus led to efforts to provide this intervention as rapidly as possible. However, studies are underway to assess whether there is improved survival after optimizing their defibrillation response strategy to achieve an 8 min response time. There is a need for a balance between the need to provide intervention, the resources available to carry out the intervention, and the cost associated with its delivery.
| Conclusion|| |
ART in Riyadh was much longer than the defined standard of 8 min and comparable to other regions of the world. Realistic response time standards should be developed instead and based upon data documenting the benefit of providing a particular intervention within a specific time frame versus the cost associated. Finally, as mechanisms for health care evolve, there must be a reevaluation and ongoing modification of time criteria.
This study has a number of limitations: data collection was performed retrospectively and was dependent on the computerized data from SRCA to identify cardiac calls to which an ambulance responded. Furthermore, this study was based on the fact that each ambulance was sent from their respective station. However, in real time, the nearest ambulance can also be dispatched during the return journey from the hospital after the conveyance of patients.
A number of studies have shown that ART by first responders is just a part in evaluating and improving the service quality of EMS systems and should include efficacy of the entire prehospital emergency care delivery process, from the onset of incident to patient handover at the emergency department.
A more complete approach toward the improvement of patient outcomes versus specific focus on ART in includes minimizing delays at each of the time components (scene-time interval, scene-to-hospital conveyance times, and vertical response time) in the service-delivery of EMS systems.
Other factors such as costs of medical care, length of hospital stay, and follow-up also indicate the benefits of ART response. These, however, will be planned for the next study.
ART studies across the world have shown that only China and Taiwan met the standard ART (i.e., ART <8 min). Therefore, adopting policies to reduce ART to <8 min (motorcycles to transport paramedics to emergency site, air ambulance, and dedicated ambulance lanes) which may detect the true association between ART and patient survival. We also recommend exclusive training of ambulatory squad and further studies after adopting the above-mentioned policies to reduce ART.
Financial support and sponsorship
Al-Imam Muhammad Ibn Saud Islamic University.
Conflicts of interest
There are no conflicts of interest.
| References|| |
Pittet V, Burnand B, Yersin B, Carron PN. Trends of pre-hospital emergency medical services activity over 10 years: A population-based registry analysis. BMC Health Serv Res 2014;14:380.
Sullivan F, Williams KA, Rhodes J. An overview of prehospital emergency medical services. R I Med J (2013) 2013;96:24-7.
Emergency Medical Services: At the Crossroads. Washington, D.C., US: Committee on the Future of Emergency Care in the United States Health System, Institute of Medicine; 2007.
O'Keeffe C, Nicholl J, Turner J, Goodacre S. Role of ambulance response times in the survival of patients with out-of-hospital cardiac arrest. Emerg Med J 2011;28:703-6.
Pell JP, Sirel JM, Marsden AK, Ford I, Cobbe SM. Effect of reducing ambulance response times on deaths from out of hospital cardiac arrest: Cohort study. BMJ 2001;322:1385-8.
Weiss S, Fullerton L, Oglesbee S, Duerden B, Froman P. Does ambulance response time influence patient condition among patients with specific medical and trauma emergencies? South Med J 2013;106:230-5.
De Maio VJ, Stiell IG, Wells GA, Spaite DW; Ontario Prehospital Advanced Life Support Study Group. Optimal defibrillation response intervals for maximum out-of-hospital cardiac arrest survival rates. Ann Emerg Med 2003;42:242-50.
Sunde K, Fremstad KO, Furuheim J, Steen PA. Ambulance response intervals in connection with cardiac arrest in Oslo. Tidsskr Nor Laegeforen 2001;121:900-3.
Yasunaga H, Miyata H, Horiguchi H, Tanabe S, Akahane M, Ogawa T, et al.
Population density, call-response interval, and survival of out-of-hospital cardiac arrest. Int J Health Geogr 2011;10:26.
Norris RM. Fatality outside hospital from acute coronary events in three British health districts, 1994-5. United Kingdom Heart Attack Study Collaborative Group. BMJ 1998;316:1065-70.
Bury G, Headon M, Egan M, Dowling J. Cardiac arrest management in general practice in Ireland: A 5-year cross-sectional study. BMJ Open 2013;3. pii: E002563.
Deasy C, Bray JE, Smith K, Harriss LR, Bernard SA, Cameron P. Out-of-hospital cardiac arrests in young adults in Melbourne, Australia. Resuscitation 2011;82:830-4.
Agarwal DA, Hess EP, Atkinson EJ, White RD. Ventricular fibrillation in Rochester, Minnesota: Experience over 18 years. Resuscitation 2009;80:1253-8.
Al-Ghamdi AS. Emergency medical service rescue times in Riyadh. Accid Anal Prev 2002;34:499-505.
EMSAT: The Emergency Medical Service Assessment Team Group, Hamam AF, Bagis MH, AlJohani K, Tashkandi AH. Public awareness of the EMS system in Western Saudi Arabia: Identifying the weakest link. Int J Emerg Med 2015;8:70.
Pointer JE. Experience and mentoring requirements for competence in new/inexperienced paramedics. Prehosp Emerg Care 2001;5:379-83.
Langhelle A, Nolan J, Herlitz J, Castren M, Wenzel V, Soreide E, et al.
Recommended guidelines for reviewing, reporting, and conducting research on post-resuscitation care: The Utstein style. Resuscitation 2005;66:271-83.
Jaldell H, Lebnak P, Amornpetchsathaporn A. Time is money, but how much? The monetary value of response time for Thai ambulance emergency services. Value Health 2014;17:555-60.
Do YK, Foo K, Ng YY, Ong ME. A quantile regression analysis of ambulance response time. Prehosp Emerg Care 2013;17:170-6.
Stoykova B, Dowie R, Bastow P, Rowsell KV, Gregory RP. Ambulance emergency services for patients with coronary heart disease in Lancashire: Achieving standards and improving performance. Emerg Med J 2004;21:99-104.
Al-Naami MY, Arafah MA, Al-Ibrahim FS. Trauma care systems in Saudi Arabia: An agenda for action. Ann Saudi Med 2010;30:50-8.
Silverman RA, Galea S, Blaney S, Freese J, Prezant DJ, Park R, et al.
The “vertical response time”: Barriers to ambulance response in an urban area. Acad Emerg Med 2007;14:772-8.
Lam SS, Nguyen FN, Ng YY, Lee VP, Wong TH, Fook-Chong SM, et al.
Factors affecting the ambulance response times of trauma incidents in Singapore. Accid Anal Prev 2015;82:27-35.
Pons PT, Haukoos JS, Bludworth W, Cribley T, Pons KA, Markovchick VJ. Paramedic response time: Does it affect patient survival? Acad Emerg Med 2005;12:594-600.
Brison RJ, Davidson JR, Dreyer JF, Jones G, Maloney J, Munkley DP, et al.
Cardiac arrest in Ontario: Circumstances, community response, role of prehospital defibrillation and predictors of survival. CMAJ 1992;147:191-9.
Stiell IG, Wells GA, Field BJ, Spaite DW, De Maio VJ, Ward R, et al.
Improved out-of-hospital cardiac arrest survival through the inexpensive optimization of an existing defibrillation program: OPALS study phase II. Ontario prehospital advanced life support. JAMA 1999;281:1175-81.
[Table 1], [Table 2], [Table 3], [Table 4]