Research, Audit & Quality Improvement Department, South Western Ambulance Service NHS Foundation Trust, Exeter, UK.
Southampton Statistical Sciences Research Institute, University of Southampton, Southampton, UK.
Emerg Med J. 2019 Apr;36(4):203-207. doi: 10.1136/emermed-2017-207354. Epub 2019 Feb 6.
A new pre-triage screening tool, Nature of Call (NoC), has been introduced into the telephone triage system of UK ambulance services which employ National Health Service Pathways (NHSP). Its function is to provide rapid recognition of patients who may need immediate ambulance dispatch for out-of-hospital cardiac arrest (OHCA) and withholding dispatch for other calls while further triage is undertaken. In this study, we evaluated the accuracy of NoC and NHSP in identifying patients with potentially treatable or imminent OHCA.
This retrospective, observational study reviewed consecutive calls to a UK ambulance service between October 2016 and February 2017 in which NOC, and then NHSP were applied sequentially. Only those calls for which a corresponding electronic Patient Clinical Record was available were included. Sensitivity and specificity of NOC and NHSP for recognition of an OHCA were determined by comparing allocated priority dispositions with an OHCA Treatment Registry (OHCATR).
Of 96 423 calls received, 71 373 were reviewed. For 590 (0.8%) of these calls, the patients received treatment for OHCA. NOC identified 458 OHCATR patients; NHSP identified 467; together they identified 496. NoC captured 29 patients not identified by NHSP; NHSP captured 38 patients not identified by NOC. For NOC sensitivity was 77.6% (95% CI 74.1 to 80.8) and specificity 86.9% (95% CI 86.6 to 87.1). NHSP sensitivity was 79.2% (95% CI 75.7 to 82.2) and specificity 93.4% (95% CI 93.2 to 93.6). NoC and NHSP combined had a sensitivity of 84.1% (95% CI 80.9 to 86.8) and specificity of 85.3% (95% CI 85.1 to 85.6).
NoC and NHSP call categorisation each achieved similar sensitivity for the identification of OHCATR, identifying most of the same patients, but each captured unique patients. Using both methods sequentially improved accuracy. The 16% of OHCATR patients not identified by either method present a challenge to ambulance dispatch systems.
Nature of Call（NoC）是一种新的分诊筛查工具，已被引入使用 National Health Service Pathways（NHSP）的英国救护车服务的电话分诊系统。其功能是快速识别可能需要立即派出救护车进行院外心脏骤停（OHCA）的患者，并在进行进一步分诊时扣留其他电话的分诊。在这项研究中，我们评估了 NoC 和 NHSP 识别具有潜在可治疗或即将发生 OHCA 的患者的准确性。
这是一项回顾性观察研究，对 2016 年 10 月至 2017 年 2 月期间英国救护车服务中心连续接到的电话进行了评估，在这些电话中，依次应用了 NoC 和 NHSP。仅包括有相应电子患者临床记录的电话。通过比较分配的优先级处置与 OHCA 治疗登记处（OHCATR），确定 NoC 和 NHSP 识别 OHCA 的敏感性和特异性。
在 96423 个收到的电话中，有 71373 个进行了审查。对于其中 590 个（0.8%）电话，患者接受了 OHCA 的治疗。NoC 识别出 458 名 OHCATR 患者；NHSP 识别出 467 名；两者共同识别出 496 名。NoC 捕获了 29 名 NHSP 未识别的患者；NHSP 捕获了 38 名 NoC 未识别的患者。对于 NoC，敏感性为 77.6%（95%CI 74.1 至 80.8），特异性为 86.9%（95%CI 86.6 至 87.1）。NHSP 的敏感性为 79.2%（95%CI 75.7 至 82.2），特异性为 93.4%（95%CI 93.2 至 93.6）。NoC 和 NHSP 联合使用的敏感性为 84.1%（95%CI 80.9 至 86.8），特异性为 85.3%（95%CI 85.1 至 85.6）。
NoC 和 NHSP 分类方法对识别 OHCATR 的敏感性均相似，识别出了大多数相同的患者，但每种方法都捕获了独特的患者。顺序使用两种方法可提高准确性。16%的 OHCATR 患者未被任何一种方法识别，这对救护车调度系统提出了挑战。
