症状指数对胃食管反流性咳嗽的诊断价值

 目的 探讨症状指数(SI)诊断胃食管反流性咳嗽(GERC)的价值及其诊断临界值。方法 回顾性分析118例可疑GERC患者的多通道食管腔内阻抗-pH监测记录,结合日记卡分别计算总SI、酸反流SI和非酸反流SI,根据药物抗反流治疗效果,评估SI对GERC的诊断价值,并与症状相关概率(SAP) 的诊断效率进行比较。结果 100例(84.7%)确诊为GERC。以总SI诊断GERC时,诊断临界值为“≥45%”时的诊断效率最高,敏感度和特异度分别为56.0%和83.3%,Youden指数为0.393;酸反流SI和非酸反流SI诊断酸或非酸GERC时,两者的最佳诊断临界值均为“≥30%”,诊断效率也相似。和SAP≥75%相比,总SI≥45%诊断GERC的灵敏度较低 (56.0%比75.0%, χ²=7.988, P=0.005),特异度较高(83.3%比44.4%, χ²=5.900,P=0.015),而阳性预计值、阴性预计值与SAP相比的差异无统计学意义。联合应用总SI和SAP能提高GERC的诊断效能。结论 总SI诊断GERC的价值与SAP相似,最佳取值以≥45%为宜。
   

The diagnostic value of symptom index in gastroesophageal reflux-induced chronic cough

Objective To explore the diagnostic value and optimal cut-off point of symptom index (SI) in gastroesophageal reflux-induced chronic cough (GERC).Methods The recordings of multichannel intraluminal esophageal impedance and pH monitoring were retrospectively analyzed in 118 patients with suspicious GERC. SI for all the refluxes, acid reflux and non-acid reflux was calculated respectively by analyzing the temporal association between detected reflux and cough recorded on diary card. Based on the favorable response to the anti-reflux therapy, the diagnostic value for GERC of SI was evaluated and compared with that of the symptom association probability (SAP).Results GERC was definitely determined in 100 patients (84.7%). When SI for all the refluxes was used for the diagnosis of GERC, the cut-off point of ≥45% had the highest diagnostic efficacy, with the sensitivity of 56.0%, the specificity of 83.3% and Youden index of 0.393. SI for acid or non-acid reflux had the same optimal cut-off point of ≥30% and presented with the similar efficacy in the diagnosis of acid or non-acid GERC. Compared with SAP of ≥75%, SI for all the refluxes of ≥45% had a lower sensitivity (56.0% vs 75.0%, χ²=7.988, P=0.005), a higher specificity (83.3% vs 44.4%,χ²=5.900,P=0.015) and the comparable positive or negative predictive value in the diagnosis of GERC. The diagnostic accuracy for GERC was further improved when combining SI for all the refluxes with SAP.Conclusion SI for all the refluxes has a diagnostic value similar to SAP and its optimal cut-off point for GERC may be ≥45%.