Abstract：
BACKGROUND: Several techniques can be used to assess bronchodilator response (BDR) in preschool-aged children, including spirometry, respiratory oscillometry, the interrupter technique, and specific airway resistance. However, there has not been a systematic comparison of BDR thresholds across studies yet.
METHODS: A systematic review was performed on all studies up to May 2023 measuring a bronchodilator effect in children 2-6 years old using one of these techniques (PROSPERO CRD42021264659). Studies were identified using MEDLINE, Cochrane, EMBASE, CINAHL via EBSCO, Web of Science databases, and reference lists of relevant manuscripts.
RESULTS: Of 1224 screened studies, 43 were included. Over 85% were from predominantly European ancestry populations, and only 22 studies (51.2%) calculated a BDR cutoff based on a healthy control group. Five studies included triplicate testing with a placebo to account for the within-subject intrasession repeatability. A relative BDR was most consistently reported by the included studies (95%) but varied widely across all techniques. Various statistical methods were used to define a BDR, with six studies using receiver operating characteristic analyses to measure the discriminative power to distinguish healthy from wheezy and asthmatic children.
CONCLUSIONS: A BDR in 2- to 6-year-olds cannot be universally defined based on the reviewed literature due to inconsistent methodology and cutoff calculations. Further studies incorporating robust methods using either distribution-based or clinical anchor-based approaches to define BDR are required.
METHODS: A systematic review was performed on all studies up to May 2023 measuring a bronchodilator effect in children 2-6 years old using one of these techniques (PROSPERO CRD42021264659). Studies were identified using MEDLINE, Cochrane, EMBASE, CINAHL via EBSCO, Web of Science databases, and reference lists of relevant manuscripts.
RESULTS: Of 1224 screened studies, 43 were included. Over 85% were from predominantly European ancestry populations, and only 22 studies (51.2%) calculated a BDR cutoff based on a healthy control group. Five studies included triplicate testing with a placebo to account for the within-subject intrasession repeatability. A relative BDR was most consistently reported by the included studies (95%) but varied widely across all techniques. Various statistical methods were used to define a BDR, with six studies using receiver operating characteristic analyses to measure the discriminative power to distinguish healthy from wheezy and asthmatic children.
CONCLUSIONS: A BDR in 2- to 6-year-olds cannot be universally defined based on the reviewed literature due to inconsistent methodology and cutoff calculations. Further studies incorporating robust methods using either distribution-based or clinical anchor-based approaches to define BDR are required.
摘要：
背景：几种技术可用于评估学龄前儿童的支气管扩张剂反应（BDR），包括肺活量测定,呼吸振荡法,断续器技术，和特定的气道阻力。然而,目前还没有系统比较不同研究的BDR阈值.
方法：对截至2023年5月的所有研究进行了系统评价，使用这些技术之一（PROSPEROCRD42021264659）测量2-6岁儿童的支气管扩张剂作用。使用MEDLINE进行研究，科克伦,EMBASE,CINAHL通过EBSCO，WebofScience数据库,以及相关手稿的参考清单。
结果：在1224项筛选研究中，43人包括在内。超过85％来自主要的欧洲血统人群，只有22项研究(51.2%)计算了基于健康对照组的BDR临界值。五项研究包括一式三份安慰剂测试，以说明受试者体内的重复性。纳入的研究（95％）报告的相对BDR最为一致，但在所有技术中差异很大。使用各种统计方法来定义BDR，六项研究使用接收器操作特征分析来测量区分健康儿童与喘息儿童和哮喘儿童的辨别能力。
结论：2至6岁儿童的BDR由于方法和截止值计算不一致，无法根据综述的文献进行普遍定义。需要结合使用基于分布或基于临床锚定的方法来定义BDR的稳健方法的进一步研究。
方法：对截至2023年5月的所有研究进行了系统评价，使用这些技术之一（PROSPEROCRD42021264659）测量2-6岁儿童的支气管扩张剂作用。使用MEDLINE进行研究，科克伦,EMBASE,CINAHL通过EBSCO，WebofScience数据库,以及相关手稿的参考清单。
结果：在1224项筛选研究中，43人包括在内。超过85％来自主要的欧洲血统人群，只有22项研究(51.2%)计算了基于健康对照组的BDR临界值。五项研究包括一式三份安慰剂测试，以说明受试者体内的重复性。纳入的研究（95％）报告的相对BDR最为一致，但在所有技术中差异很大。使用各种统计方法来定义BDR，六项研究使用接收器操作特征分析来测量区分健康儿童与喘息儿童和哮喘儿童的辨别能力。
结论：2至6岁儿童的BDR由于方法和截止值计算不一致，无法根据综述的文献进行普遍定义。需要结合使用基于分布或基于临床锚定的方法来定义BDR的稳健方法的进一步研究。
