Zimmerli Lukas, Steurer Johann, Kofmehl Reto, Wertli Maria M, Held Ulrike
Horten Centre for Patient Oriented-Research and Knowledge Transfer, University of Zurich, Pestalozzistrasse 24, Zurich 8091, Switzerland.
BMC Emerg Med. 2014 Nov 18;14:23. doi: 10.1186/1471-227X-14-23.
We recently reported about the derivation of a diagnostic probability function for acute coronary syndrome (ACS). The present study aims to validate the probability function as a rule-out criterion in a new sample of patients.
186 patients presenting with chest pain and/or dyspnea at one of the three participating hospitals' emergency rooms in Switzerland were included in the study. In these patients, information on a set of pre-specified variables was collected and a predicted probability of ACS was calculated for each patient. Approximately two weeks after the initial visit in the emergency room, patients were contacted by phone to assess whether a diagnosis of ACS was established.
Of the 186 patients included in the study, 31 (17%) had an acute coronary syndrome. A risk probability for ACS below 2% was considered a rule-out criterion for ACS, leading to a sensitivity of 87% and a specificity of 17% of the rule. The characteristics of the study patients were compared to the cases from which the probability function was derived, and considerable deviations were found in some of the variables.
The proposed probability function, with a 2% cut-off for ruling out ACS works quite well if the patient data lie within the ranges of values of the original vignettes. If the observations deviate too much from these ranges, the predicted probabilities for ACS should be seen with caution.
我们最近报告了急性冠状动脉综合征（ACS）诊断概率函数的推导。本研究旨在验证该概率函数作为新患者样本中排除标准的有效性。
纳入了在瑞士三家参与研究的医院之一的急诊室就诊的186例胸痛和/或呼吸困难患者。收集这些患者一组预先指定变量的信息，并为每位患者计算ACS的预测概率。在急诊室首次就诊约两周后，通过电话联系患者以评估是否确诊为ACS。
在纳入研究的186例患者中，31例（17%）患有急性冠状动脉综合征。ACS风险概率低于2%被视为ACS的排除标准，该标准的敏感性为87%，特异性为17%。将研究患者的特征与推导概率函数所依据的病例进行比较，发现一些变量存在显著差异。
如果患者数据处于原始案例的值范围内，所提出的用于排除ACS的概率函数（截断值为2%）效果良好。如果观察结果与这些范围偏差过大，则应谨慎看待ACS的预测概率。
