Prehospital triage accuracy in a criteria based dispatch centre

BMC Emergency Medicine

Olivier Hugli³  Pierre-Nicolas Carron³  Vincent Fuchs²  Mathieu Pasquier³  Christel Golay¹  Fabrice Dami³ 

[1] Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland;Dispatch centre, State of Vaud (Fondation Urgences-Santé), César-Roux 31, Lausanne, 1005, Switzerland;Department of Emergency Medicine, University Hospital Center (CHUV), Bugnon 46, Lausanne, 1011, Switzerland

关键词: Benchmarking;    Accuracy;    Criteria-based dispatch;    EMS;   

Others  :  1233949
DOI  :  10.1186/s12873-015-0058-x

 received in 2015-06-03, accepted in 2015-10-19,  发布年份 2015

【 摘 要 】

Background

Priority dispatch accuracy is a key issue in optimizing the match between patients’ medical needs and pre-hospital resources. This study measures the accuracy of a Criteria Based Dispatch (CBD) system, by evaluating discrepancies between dispatch priorities and ambulance crews’ severity evaluations.

Methods

This is a retrospective study conducted from January 2011 to December 2011. We ruled that a National Advisory Committee for Aeronautics (NACA) score > 3 (injuries/diseases which can possibly lead to deterioration of vital signs) to 7 (lethal injuries/ diseases) should require a priority dispatch with lights and siren (L&S), while NACA scores < 4 should require a priority dispatch without L&S. Over triage was defined as the proportion of L&S dispatches with a NACA score < 4, and under triage as the proportion of dispatches without L&S with a NACA score > 3.

Results

There were 29,008 primary missions in 2011, 1122 were excluded. Of the 15,749 L&S missions, 12,333 patients had a NACA score < 4, leading to an over triage rate of 78 %; 561 missions out of 12,137 missions without L&S had a NACA score > 3, leading to an under triage rate of 4.6 %. Sensitivity was 86 % (95 % confidence interval: 85.6–86.4 %), specificity 48 % (47.4–48.6 %), positive predictive value 21.7 % (21.2–22.2 %), and negative predictive value 95.4 % (95.2–95.6 %).

Conclusion

The rates of over triage and under triage in our CBD are 78 and 4.6 % respectively. The lack of consistent or universal metrics is perhaps the most important limitation in dispatch accuracy research. This is mainly due to the large heterogeneity of dispatch systems and prehospital emergency system.

【 授权许可】

   
2015 dami et al.

【 图 表 】

Fig. 1.

Fig. 2.

【 参考文献 】

• [1]Snooks H, Evans A, Wells B, Peconi J, Thomas M, Woollard M et al.. What are the highest priorities for research in emergency prehospital care? Emerg Med J. 2009; 26:549-550.
• [2]Maguire JB, Hunting KL, Smith GS, Levick NR. Occupational fatalities in EMS: a hidden crisis. Ann Emerg Med. 2002; 40:625-632.
• [3]Merlin M, Baldino KT, Lehrfeld DP, Linger M, Lustiger E, Cascio A et al.. Use of a limited lights and siren protocol in the prehospital setting vs. standard usage. Am J Emerg Med. 2012; 30:519-525.
• [4]MacKenzie EJ, Rivara FP, Jurkovich GJ, Nathens AB, Frey KP, Egleston BL et al.. A national evaluation of the effect of trauma-center care on mortality. NEJM. 2006; 354:366-378.
• [5]Sporer KA, Johnson NJ, Clement CY, Youngblood GM. Can emergency medical dispatch codes predict prehospital interventions for common 9-1-1 call types ? Prehosp Emerg Care. 2008; 12:470-478.
• [6]Feldman MJ, Verbeek PR, Lyons DG, Chad SJ, Craig AM, Schwartz B. Comparison of the medical priority dispatch system to an out-of-hospital patient acuity score. Acad Emerg Med. 2006; 13:954-960.
• [7]Clegg GR, Lyon RM, James S, Branigan HP, Bard EG, Dispatch-assisted EGJ et al.. Where are the hold-ups during calls to emergency dispatchers? a preliminary analysis of caller–dispatcher interactions during out-of-hospital cardiac arrest using a novel call transcription technique. Resuscitation. 2014; 85:49-52.
• [8]Andersen MS, Johnsen SP, Sørensen JN, Jepsen SB, Hansen JB, Christensen EF. Implementing a nationwide criteria-based emergency medical dispatch system: a register-based follow-up study. Scand J Trauma Resusc Emerg Med. 2013; 21:53. BioMed Central Full Text
• [9]Zakariassen E, Burman RA, Hunskaar S. The epidemiology of medical emergency contacts outside hospitals in Norway - a prospective population based study. Scand J Trauma Resusc Emerg Med. 2010; 18:9. BioMed Central Full Text
• [10]Stipulante S, Tubes R, El Fassi M, Donneau AF, Van Troyen B, Hartstein G et al.. Implementation of the ALERT algorithm, a new dispatcher-assisted telephone cardiopulmonary resuscitation protocol, in non-advanced medical priority dispatch system (AMPDS) emergency medical services centres. Resuscitation. 2014; 85:177-181.
• [11]Dami F, Rossetti AO, Fuchs V, Yersin B, Hugli O. Proportion of out-of-hospital adult non-traumatic cardiac or respiratory arrest among calls for seizure. Emerg Med J. 2012; 29:758-760.
• [12]Adnet F, Lapostolle F. International EMS systems: France. Resuscitation. 2004; 63:7-9.
• [13]Dami F, Fuchs V, Praz L, Vader JP. Introducing systematic dispatcher-assisted cardiopulmonary resuscitation (telephone-CPR) in a non-advanced medical priority dispatch system (AMPDS): implementation process and costs. Resuscitation. 2010; 81(7):848-852.
• [14]Official Swiss dispositions for medical dispatch, IAS. http://www.ivr-ias.ch/cms/upload/imgfile1534.pdf, last visited April 14th 2015
• [15]State of Vaud, Paramedics’ protocols. www. bc-cesu.ch/pdf/AlgoVD_revision2010-11_v6_16.08.12_LPSD.pdf webcite
• [16]Tryba M, Brüggemann H, Echtermeyer V. Klassifizierung von erkrankungen und verletzungen im notarztrettungssystemen. Notfallmedizin. 1980; 6:725-727.
• [17]Weiss M, Bernoulli L, Zollinger A. The NACA scale. Construct and predictive validity of the NACA scale for prehospital severity rating in trauma patients. Anaesthesist. 2001; 50:150-154.
• [18]Sefrin P, Sellner J. Qualitätssicherung in der präklinischen Notfallmedizin. Notfallmedizin. 1993; 19:267-274.
• [19]Bonatti J, Göschl O, Larcher P, Wödlinger R, Flora G. Predictors of short-term survival after helicopter rescue. Resuscitation. 1995; 30:133-140.
• [20]Resources for optimal care of injured patient. American College of Surgeons-COT, Chicago; 2006.
• [21]Mann NC, Schmidt TA, Cone DC. Defining research criteria to characterize medical necessity in emergency medical services: a consensus among experts at the Neely Conference. Prehosp Emerg Care. 2004; 8:138-153.
• [22]Hettinger AZ, Cushman JT, Shah MN, Noyes K. Emergency medical dispatch codes association with emergency department outcomes. Prehosp Emerg Care. 2013; 17:29-37.
• [23]Khorram-Manesh A, Montán KL, Hedelin A, Kihlgren M, Örtenwall P. Prehospital triage, discrepancy in priority-setting between emergency medical dispatch centre and ambulance crews. Eur J Trauma Emerg Surg. 2011; 37:73-78.
• [24]Scott G. The need for 911 research and its impact on operations. Ann Emerg Disp Resp. 2013; 1:16-17.
• [25]Eisenberg MS, Bergner L, Hallstrom A. Cardiac resuscitation in the community. Importance of rapid provision and implications for program planning. JAMA. 1979; 241:1905-1907.
• [26]Wilson S, Cooke M, Morrell R, Bridge P, Allan T. A systematic review of the evidence supporting the use of priority dispatch of emergency ambulances. Prehosp Emerg Care. 2002; 6:42-49.
• [27]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.
• [28]Scerbo M, Radhakrishnan H, Cotton B, Dua A, Del Junco D, Wade C et al.. Prehospital triage of trauma patients using the random forest computer algorithm. J Surg Res. 2014; 187:371-376.
• [29]Ohshige K, Kawakami C, Mizushima S, Moriwaki Y, Suzuki N. Evaluation of an algorithm for estimating a patient’s life threat risk from an ambulance call. BMC Emerg Med. 2009; 9:21. BioMed Central Full Text
• [30]Schlechtriemen T, Burghofer K, Lackner CK, Altemeyer KH. Validierung des NACA-Scoreanhand objektivierbarer Parameter. Notfall&Rettungsmedizin. 2005; 8:96-108.
• [31]Knapp J, Bernhard M, Hainer C, Sikinger M, Brenner T, Schlechtriemen T et al.. Is there an association between the rating of illness and injury severity and the experience of emergency medical physicians? Anaesthesist. 2008; 57:1069-1074.
• [32]Lindström V, Karlsten R, Falk A-C, Castrèn M. Feasibility of a computer-assisted feedback system between dispatch centre and ambulances. Eur J Emerg Med. 2011; 18:143-1.
• [33]Ek B, Edstrom P, Toutin, Svedlund M. Reliability of a Swedish pre-hospital dispatch system in prioritizing patients. Int Emergy Nurs. 2013; 21:143-149.
• [34]Lu TC, Chen YT, Chow-In Ko P, Lin CH, Shih FY, Yen ZS et al.. The demand for prehospital advanced life support and the appropriateness of dispatch in Taipei. Resuscitation. 2006; 71:171-179.
• [35]Sporer KA, Youngblood GM, Rodriguez RM. The ability of emergency medical dispatch codes of medical complaints to predict ALS prehospital interventions. Prehosp Emerg Care. 2001; 11:192-198.
• [36]Neely KW, Eldurkar JA, Drake ME. Do emergency medical services dispatch nature and severity codes agree with paramedic field findings? Acad Emerg Med. 2000; 7:174-180.