由于在不发达国家缺乏标准化的医疗服务、卫生保健设施不足,世界范围内的发病率尚不清楚。在美国,据估计有 110,000 人患支气管扩张症, [6]Weyker D, Edelsberg J, Oster G, et al. Prevalence and economic burden of bronchiectasis. Clin Pulm Med. 2005;12:205. 但数据显示,患病率在不断升高。[7]Seitz AE, Olivier KN, Adjemian J, et al. Trends in bronchiectasis among medicare beneficiaries in the United States, 2000 to 2007. Chest. 2012;142:432-439.http://journal.publications.chestnet.org/article.aspx?articleid=1262336http://www.ncbi.nlm.nih.gov/pubmed/22302301?tool=bestpractice.com 支气管扩张症随着年龄增长越来越常见,发病率范围可从 18-34 岁年龄组的 4.2/100,000 到 75 岁以上年龄组的 272/100,000。[6]Weyker D, Edelsberg J, Oster G, et al. Prevalence and economic burden of bronchiectasis. Clin Pulm Med. 2005;12:205.
在英国,发病率为 1.06-1.3/100,000。[8]British Thoracic Society Standards of Care Committee. BTS statement on criteria for specialist referral, admission, discharge and follow-up for adults with respiratory disease. Thorax. 2008;63(suppl 1):i1-i16.http://thorax.bmj.com/content/63/Suppl_1/i1.longhttp://www.ncbi.nlm.nih.gov/pubmed/18308973?tool=bestpractice.com 新西兰的一项研究估计,儿童发病率高达 3.7/100,000;不同种族的发病率不同,太平洋地区儿童发病率最高,为 17.8/100,000。[9]Twiss J, Metcalfe R, Edwards E, et al. New Zealand national incidence of bronchiectasis "too high" for a developed country. Arch Dis Child. 2005;90:737-740.http://www.ncbi.nlm.nih.gov/pubmed/15871981?tool=bestpractice.com
世界范围内,许多患者存在明确病因,尤其由既往感染导致的支支气管扩张症。然而,支气管扩张症的病因也可能不明确,这种情况通常被认为是特发性支气管扩张症。先天性疾病和免疫失调(自身免疫或免疫缺陷)也可能引起支气管扩张症。[10]McShane PJ, Naureckas ET, Strek ME. Bronchiectasis in a diverse US population: effects of ethnicity on etiology and sputum culture. Chest. 2012;142:159-167.http://www.ncbi.nlm.nih.gov/pubmed/22267679?tool=bestpractice.com
多变量分析显示下列因素可独立预测中到重度支气管扩张症患者的死亡率:[11]Loebinger MR, Wells AU, Hansell DM, et al. Mortality in bronchiectasis: a long term study assessing the factors influencing survival. Eur Respir J. 2009;34:843-849.http://www.ncbi.nlm.nih.gov/pubmed/19357155?tool=bestpractice.com