Kellerer Christina, Hapfelmeier Alexander, Jörres Rudolf A, Schultz Konrad, Brunn Benjamin, Schneider Antonius
Technical University of Munich, School of Medicine, Institute of General Practice and Health Services Research, Munich, Germany
Technical University of Munich, School of Medicine, Institute of General Practice and Health Services Research, Munich, Germany.
BMJ Open. 2021 Feb 12;11(2):e045420. doi: 10.1136/bmjopen-2020-045420.
The measurement of fractional exhaled nitric oxide (FeNO) is promising for diagnosing asthma and might substitute for bronchial provocation (BP) tests. To evaluate the diagnostic accuracy of FeNO within a confirmatory study, the following hypotheses will be tested: (1) A FeNO cut-off >50 ppb (parts per billion) is suitable for diagnosing asthma (sensitivity 35%, specificity 95%); (2) If the clinical symptoms 'allergic rhinitis' and 'wheezing' are present, asthma can be diagnosed at FeNO >33 ppb with a positive predictive value (PPV) 70% and (3) A FeNO >33 ppb can predict responsiveness to inhaled corticosteroid (ICS) with a PPV 70%.
A prospective diagnostic study will be conducted in three practices of pneumologists in Germany. 300 patients suspected of suffering from asthma will be included. As an index test, patients perform FeNO measurement with the device NIOX VERO. As reference a test, patients are examined with whole bodyplethysmography and BP, if necessary. After 3 months, patients with an asthma diagnosis will be examined again to verify the diagnosis and evaluate ICS responsiveness. Patients who did not receive an asthma diagnosis at the initial examination will be phoned after 3 months and asked about persistent respiratory symptoms to exclude false negative findings. As a primary target, sensitivity and specificity of FeNO >50 ppb will be determined. As a secondary target the PPV for asthma at FeNO >33 ppb, when the symptoms 'allergic rhinitis' and 'wheezing' are present, will be calculated. Regarding ICS responsiveness, the PPV of FeNO >33 ppb will be determined.
The study was approved by the Ethical Committee of the Technical University of Munich (Reference number 122/20 S). The major results will be published in peer-reviewed academic journals and disseminated through conferences.
DRKS00021125.
呼出一氧化氮分数（FeNO）测量在哮喘诊断方面颇具前景，可能会替代支气管激发（BP）试验。为在一项验证性研究中评估FeNO的诊断准确性，将检验以下假设：（1）FeNO临界值>50 ppb（十亿分之一）适用于哮喘诊断（敏感性35%，特异性95%）；（2）若存在“过敏性鼻炎”和“喘息”等临床症状，则FeNO>33 ppb时可诊断哮喘，阳性预测值（PPV）为70%；（3）FeNO>33 ppb可预测对吸入性糖皮质激素（ICS）的反应性，PPV为70%。
将在德国三位肺科医生的诊所开展一项前瞻性诊断研究。纳入300例疑似哮喘患者。作为指标检测，患者使用NIOX VERO设备进行FeNO测量。作为参考检测，必要时患者接受全身体积描记法和BP检查。3个月后，对已诊断为哮喘的患者再次进行检查，以验证诊断并评估ICS反应性。对初次检查未诊断为哮喘的患者，3个月后致电询问持续性呼吸道症状，以排除假阴性结果。作为主要目标，确定FeNO>50 ppb的敏感性和特异性。作为次要目标，计算存在“过敏性鼻炎”和“喘息”症状时，FeNO>33 ppb诊断哮喘的PPV。关于ICS反应性，确定FeNO>33 ppb的PPV。
该研究获慕尼黑工业大学伦理委员会批准（参考编号122/20 S）。主要研究结果将发表在同行评审的学术期刊上，并在会议上进行传播。
DRKS00021125。
