Lang A, Carlsen K H, Haaland G, Devulapalli C S, Munthe-Kaas M, Mowinckel P, Carlsen K
Department of Pediatrics, Ullevål University Hospital, Oslo, Norway.
Allergy. 2008 Aug;63(8):1054-60. doi: 10.1111/j.1398-9995.2008.01672.x.
Limited information is available regarding the prevalence of severe asthma in children. The present study aimed at investigating the prevalence of severe asthma in an urban child population; secondarily evaluating the applicability of the chosen definition by clinical characteristics.
Children enrolled in the prospective birth cohort; the Environment and Childhood Asthma Study in Oslo; were reinvestigated at the age of 10 years (n = 1019). A representative population based cohort of 616 children [mean age 10.9 (SD 0.9) years] with lung function measurements at birth was used for prevalence estimates, whereas all 1019 children (154 with current asthma) attending the 10-year follow-up were included for verification of the definition of severe asthma. Clinical investigations included spirometry, tests of bronchial hyperresponsiveness, skin prick tests and exhaled nitric oxide. Severe asthma was defined as poorly controlled asthma despite treatment with > or = 800 microg budesonide or equivalent; assessed by a detailed structured interview.
The population point prevalence at age 10 years of current severe asthma was 0.5% (three of 616) and among children with current asthma 4.5% (three of 67). The 10/154 children identified as suffering from severe asthma more often had severe bronchial hyperresponsiveness (PD(20) methacholine <1 micromol) (60%vs 22%, P = 0.015), lower median forced expiratory volume in 1 s/forced vital capacity ratio (93%vs 99%, P = 0.04) and higher body mass index (mean BMI 22.3 vs 18.3, P < 0.001) than nonsevere current asthmatics.
The prevalence of severe asthma was 0.5% in all 10-year olds, and 4.5% among current asthmatics. The severe asthma definition applied in this study is supported by results of clinical investigations.
关于儿童重度哮喘患病率的信息有限。本研究旨在调查城市儿童人群中重度哮喘的患病率；其次，根据临床特征评估所选定义的适用性。
对参与前瞻性出生队列研究（奥斯陆环境与儿童哮喘研究）的儿童在10岁时进行再次调查（n = 1019）。以616名有出生时肺功能测量数据的儿童（平均年龄10.9岁，标准差0.9岁）为代表性人群队列来估计患病率，而参加10年随访的所有1019名儿童（154名目前患有哮喘）均纳入以验证重度哮喘的定义。临床检查包括肺功能测定、支气管高反应性测试、皮肤点刺试验和呼出一氧化氮检测。重度哮喘定义为尽管使用≥800微克布地奈德或等效药物治疗但哮喘仍控制不佳；通过详细的结构化访谈进行评估。
10岁时当前重度哮喘的人群点患病率为0.5%（616名中的3名），在当前患有哮喘的儿童中为4.5%（67名中的3名）。被确定患有重度哮喘的10/154名儿童与非重度当前哮喘患者相比，更常出现严重支气管高反应性（乙酰甲胆碱PD(20)<1微摩尔）（60%对22%，P = 0.015），1秒用力呼气量/用力肺活量比值中位数更低（93%对99%，P = 0.04），体重指数更高（平均BMI 22.3对18.3，P < 0.001）。
所有10岁儿童中重度哮喘的患病率为0.5%，当前哮喘患者中为4.5%。本研究中应用的重度哮喘定义得到了临床调查结果的支持。
