Supplementary Material for: Effect of Bronchodilators on Forced Expiratory Volume in 1 s in Preterm-Born Participants Aged 5 and Over: A Systematic Review

Background and Objectives: Preterm-born participants are at risk of long-term deficits in percentage predicted forced expiratory volume in 1 s (þV1). Since it is unclear if these deficits respond to bronchodilators, we systematically reviewed the evidence for reversibility of deficits in þV1 by bronchodilators in preterm-born participants. Design: Studies reporting a change in þV1 in response to bronchodilator treatment in preterm-born participants at ≥5 years of age, with or without a term-born control group, were identified. The quality of studies was assessed by adapted tools. Due to considerable heterogeneity between studies, formal meta-analysis was not possible. Results: From 8,839 titles, 22 studies were identified after an updated search in May 2013. Twenty-one studies assessed the response to a single inhaled dose of a bronchodilator, and 1 study assessed longer-term effects. Most studies observed decreased þV1 in preterm-born participants compared with controls. Most studies observed improved þV1 after a single dose of bronchodilator, with the largest improvements noted in those with bronchopulmonary dysplasia, who had greater deficits of þV1 when compared with preterm and term controls. One long-term study investigated a 2-week terbutaline administration, but the initial FEV1 after a single dose did not show a change in þV1 of ≥15%, but 5/29 (17%) children had an increased þV1 of ≥10%. Conclusions: In this systematic review, disparate studies were identified. Although single doses of bronchodilators appear to improve the FEV1 in the short term, further studies are required to assess their longer-term benefits not only on airway obstruction, but also their effect on respiratory symptoms.

背景与研究目的：早产出生人群存在长期的一秒用力呼气容积占预计值百分比（þV1）缺损风险。目前尚不明确此类缺损是否可经支气管扩张剂改善，因此本研究对早产出生人群中支气管扩张剂对þV1缺损的可逆性相关证据进行了系统综述。
研究设计：筛选纳入了针对≥5岁早产出生人群、报告支气管扩张剂治疗后þV1变化的研究，此类研究可设置或不设置足月出生对照组。采用改良工具对研究质量进行评估。由于各研究间异质性显著，无法开展正式的荟萃分析。
研究结果：2013年5月更新检索后，从8839篇文献题名中筛选出22项符合条件的研究。其中21项研究评估了单次吸入剂量支气管扩张剂的干预效果，1项研究评估了长期干预效应。多数研究显示，与对照组相比，早产出生人群的þV1水平更低。多数研究观察到单次支气管扩张剂给药后þV1水平得到改善，其中合并支气管肺发育不良的受试者改善最为显著，相较于早产及足月对照组，该群体的þV1缺损程度更为严重。1项长期研究评估了为期2周的特布他林给药干预，但单次给药后的初始FEV1未出现≥15%的þV1变化；不过29名受试者中有5名（17%）的þV1升高幅度≥10%。
研究结论：本项系统综述共纳入异质性较强的多项研究。尽管单次剂量支气管扩张剂可在短期内改善FEV1，但仍需开展进一步研究以评估其长期获益，不仅需关注其对气道阻塞的改善作用，还需探究其对呼吸道症状的影响。