Center for Child Health Care Studies, Department of Population Medicine, Harvard Pilgrim Health Care Institute and Harvard Medical School, Boston, MA; Department of Pediatrics, Children's Hospital, Boston, MA; Harvard Medical School, Department of Medicine, Brigham and Women's Hospital, Boston, MA.
Harvard Medical School, Department of Medicine, Brigham and Women's Hospital, Boston, MA; Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, Boston, MA; Center for Genomic Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA.
Chest. 2011 Jul;140(1):100-107. doi: 10.1378/chest.10-2794. Epub 2011 Feb 3.
Asthma therapy is typically prescribed and titrated based on patient or parent self-report of symptoms. No longitudinal studies have assessed the relationship between symptoms and severe asthma exacerbations in children. The goal of our study was (1) to assess the association of asthma symptoms with severe asthma exacerbations and (2) to compare predictors of persistent asthma symptoms and predictors of severe asthma exacerbations.
The Childhood Asthma Management Program was a multicenter clinical trial of 1,041 children randomized to receive budesonide, nedocromil, or placebo (as-needed β-agonist). We conducted a post hoc analysis of diary cards that were completed by subjects on a daily basis to categorize subjects as having persistent vs intermittent symptoms. We defined a severe asthma exacerbation as an episode requiring ≥ 3 days use of oral corticosteroids, hospitalization, or ED visit due to asthma based on self-report at study visits every 4 months.
While accounting for longitudinal measures, having persistent symptoms from asthma was significantly associated with having severe asthma exacerbations. Predictors of having persistent symptoms compared with intermittent symptoms included not being treated with inhaled corticosteroids, lower FEV(1)/FVC ratio, and a lower natural logarithm of provocative concentration of methacholine producing a 20% decline in FEV(1) (lnPC(20)). Predictors of having one or more severe asthma exacerbations included younger age, history of hospitalization or ED visit in the prior year, ≥ 3 days use of oral corticosteroids in the prior 3 months, lower FEV(1)/FVC ratio, lower lnPC(20), and higher logarithm to the base 10 eosinophil count; treatment with inhaled corticosteroids was predictive of having no severe asthma exacerbations.
Patients with persistent symptoms from asthma were more likely to experience severe asthma exacerbations. Nevertheless, demographic and laboratory predictors of having persistent symptoms are different from predictors of severe asthma exacerbations. Although symptoms and exacerbations are closely related, their predictors are different. The current focus of the National Asthma Education and Prevention Program guidelines on the two separate domains of asthma control, impairment and risk, are supported by our analysis.
哮喘治疗通常根据患者或家长报告的症状来开具处方和滴定剂量。目前尚无研究评估儿童的哮喘症状与重度哮喘发作之间的关系。我们的研究目的是：(1)评估哮喘症状与重度哮喘发作之间的关联；(2)比较持续性哮喘症状和重度哮喘发作的预测因素。
儿童哮喘管理计划（Childhood Asthma Management Program）是一项多中心临床试验，共纳入 1041 例患儿，随机分配至布地奈德、奈多罗米、或安慰剂（按需使用β激动剂）组。我们对患儿每天填写的日记卡进行了一项事后分析，根据研究期间每 4 个月的自我报告，将患儿分为持续性症状或间歇性症状。我们将需要≥3 天口服皮质激素、住院或因哮喘就诊于急诊室定义为重度哮喘发作。
在考虑了纵向测量指标后，持续性哮喘症状与重度哮喘发作显著相关。与间歇性症状相比，持续性症状的预测因素包括未接受吸入皮质激素治疗、较低的 FEV1/FVC 比值、以及较低的激发试验中使 FEV1 下降 20%的乙酰甲胆碱浓度的自然对数值（lnPC20）。预测发生 1 次或多次重度哮喘发作的因素包括年龄较小、前一年有住院或急诊就诊史、前 3 个月中使用≥3 天的口服皮质激素、较低的 FEV1/FVC 比值、较低的 lnPC20、以及较高的以 10 为底的对数嗜酸粒细胞计数；接受吸入皮质激素治疗是不发生重度哮喘发作的预测因素。
持续性哮喘症状的患者更有可能经历重度哮喘发作。然而，持续性症状的预测因素与重度哮喘发作的预测因素不同。尽管症状和发作密切相关，但它们的预测因素不同。国家哮喘教育和预防计划指南对哮喘控制的两个独立领域（即损伤和风险）的关注，得到了我们的分析支持。
