INTRODUCTION

Ambulance times are internationally recognised Key Performance Indicators (KPIs) for prehospital care¹. However, the terminology and definitions surrounding ambulance times and time intervals are not standardised across countries^1-3. This can pose challenges for clinicians and researchers when synthesising international evidence or comparing countries/regions in this context. Standardization or alignment of terminology and definitions would accommodate more accurate international comparison.

International benchmarking, by comparing ambulance times between countries is a valuable method to help to identify strengths and weakness across healthcare systems⁴. Benchmarking has a long history of being used in the healthcare sector to compare outcomes across organisations^4. It also facilitates shared learning and application of best practice⁴. If applied correctly, benchmarking can highlight unnecessary variation and work to reduce its occurrence⁴.

This study aims to compare terminology and definitions of ambulance times and time intervals from the ambulance services of a range of countries to facilitate international benchmarking.

Methods

Terminology versus definition

In the context of this study, we consider “terminology” as the term used to describe an ambulance time or ambulance time intervals. Whereas a “definition” is the variable that constitute the time or time interval on the computer aided dispatch (CAD) system.

Ambulance times and ambulance time intervals

An ambulance “time” is “a specific event within the emergency medical services (EMS) response”, such as at scene time5. Whereas an ambulance time “interval” is “the temporal distance between two times”, such as response time/interval5.

In this study we were interested in key points of the patient journey from time call commenced to arrival at the hospital6. These times and intervals were chosen due to their clinical significance and also as they are commonly reported in the EMS response literature2,3. EMS organisation ambulance time intervals can be measured from alternate starting points to “time calling taking commenced”, when reporting to standards authorities1. This can include the “T5” time, when the Advanced Medical Priority Dispatch System (AMPDS) code7 is assigned to the call.  However, in the EMS response literature, the patient-centred perspective is commonly taken, where the prehospital response begins at “time calling taking commenced”1-3.

The benchmark used for this international comparison were the ambulance times and intervals terminology and definitions used by the Republic of Ireland National Ambulance Service (Table 1)8. The authors have recently formed the Prehospital Care of Stroke consortium and within this consortium, we plan to compare ambulance times and intervals from the Republic of Ireland with other participating  countries. Thus, terminology and definitions needed to be explored amongst the consortium prior to further work.

 

References:

1.     Health Information and Quality Authority: Pre-hospital Emergency Care 
Key Performance Indicators for Emergency Response Times. Ireland: Health Information and Quality Authority; 2012; 84.
2.     Breen N, Woods J, Bury G, et al.: A national census of ambulance response times to emergency calls in Ireland. J Accid Emerg Med. 2000; 17(6): 392–5.
3.     Harmsen AM, Giannakopoulos GF, Moerbeek PR, Jansma EP, Bonjer HJ, Bloemers FW. The influence of prehospital time on trauma patients’ outcome: a systematic review. Injury. 2015;46(4):602-9.
4.     Willmington C, Belardi P, Murante AM, Vainieri M. The contribution of benchmarking to quality improvement in healthcare. A systematic literature review. BMC Health Serv Res. 2022;22(1):139.
5.     Spaite DW, Valenzuela TD, Meislin HW, Criss EA, Hinsberg P. Prospective validation of a new model for evaluating emergency medical services systems by in-field observation of specific time intervals in prehospital care. Ann Emerg Med. 1993 Apr;22(4):638-45.
6.     Krafft T, García Castrillo-Riesgo L, Edwards S, Fischer M, Overton J, Robertson-Steel I, König A. European Emergency Data Project (EED Project): EMS 
data-based health surveillance system. Eur J Public Health. 2003 Sep;13(3 Suppl):85-90. doi: 10.1093/eurpub/13.suppl_1.85. PMID: 14533755.
7.     Sporer KA, Johnson NJ. Detailed analysis of prehospital interventions 
in medical priority dispatch system determinants. West J Emerg Med.
2011;12(1):19-29.
8.     Health Information and Quality Authority: Pre-hospital Emergency Care 
Key Performance Indicators for Emergency Response Times. Ireland: Health Information and Quality Authority;2012;84. Available from: Pre-hospital Emergency Care Key Performance Indicators for Emergency Response Times Version 1.1 | HIQA
9.     Pre-hospital Emergency Care Council: STN001 EMS Priority Dispatch Standard Version 4. Kildare: Pre-hospital Emergency Care Council; 2014. 10p. Available from: https://www.phecit.ie/Images/PHECC/Clinical%20resources/STN001%20EMS%20Priority%20Dispatch%20Standard%20V4.pdf.
10.     1Lu Y, Xu Y, Herrera-Viedma E, Han Y. Consensus of large-scale group decision making in social network: the minimum cost model based on robust optimization. Inf Sci (N Y). 2021; 547:910-30.
11.     Burton E. Speaking the same language with Edel Burton. Dispatch in Depth [ Internet]. Utah: Annals of Emergency Dispatch and Response;2023 Feb 21. Available from: Speaking the Same Language with Edel Burton - AEDR Journal. https://www.aedrjournal.org/speaking-the-same-language-with-edel-burton
12.     NHS. Ambulance Quality Indicators: Clinical Outcomes specification. United Kingdom, NHS; 2021;12.