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

<b><i>Background and Objectives:</i></b> 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. <b><i>Design:</i></b> 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. <b><i>Results:</i></b> 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%. <b><i>Conclusions:</i></b> 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**：早产受试者存在长期一秒用力呼气容积（forced expiratory volume in one second, FEV₁）占预计值百分比缺损的风险。目前尚不明确此类缺损是否可通过支气管舒张剂（bronchodilators）得到改善，因此本系统评价旨在梳理早产受试者经支气管舒张剂治疗后FEV₁缺损可逆性的相关证据。
**研究设计**：纳入针对≥5岁早产受试者接受支气管舒张剂治疗后FEV₁变化的相关研究，此类研究可设置或不设置足月出生的对照组。研究质量采用经过改良的评价工具进行评估。由于各研究间异质性显著，无法开展规范的Meta分析（meta-analysis）。
**研究结果**：2013年5月更新检索后，从8839条文献题录中最终纳入22项研究。其中21项研究评估了单次吸入剂量支气管舒张剂的应答效果，1项研究评估了长期用药的效应。多数研究显示，与对照组相比，早产受试者的FEV₁水平更低。单次使用支气管舒张剂后，多数研究观察到受试者FEV₁水平有所改善，其中合并支气管肺发育不良（bronchopulmonary dysplasia, BPD）的受试者改善最为显著——此类人群相较于早产及足月对照组，FEV₁的缺损程度更为严重。另有1项长期研究探讨了为期2周的特布他林（terbutaline）给药方案，但单次给药后的初始FEV₁并未出现≥15%的变化，不过29名儿童中有5名（17%）的FEV₁提升幅度≥10%。
**研究结论**：本项系统评价共纳入多项异质性较强的研究。尽管单次使用支气管舒张剂可在短期内改善FEV₁水平，但仍需开展进一步研究，以评估其长期获益：不仅需明确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。