Purpose: Current guidelines primarily use medication levels to distinguish severe asthma from other types of asthma. In addition, severe asthma must also be uncontrolled at high-intensity treatment or become uncontrolled if treatment level is decreased. To date, only a few studies have used this definition to investigate the prevalence and clinical characteristics of severe asthma in population-based samples. Therefore, the aim of this study was to evaluate the prevalence and clinical characteristics of individuals with severe asthma in the population-representative West Sweden Asthma Study.
Materials and Methods: In this cross-sectional population-based study, a randomly selected sample (n=1172) and a separate asthma sample (n=744) underwent clinical examinations, completed a structured interview and responded to questionnaires. Severe asthma was defined as at least one feature of uncontrolled asthma despite treatment in line with the Global Initiative for Asthma (GINA) steps 4/5. This treatment level required a minimum medium dose of inhaled corticosteroids (ICS) plus a second controller or oral corticosteroids.
Results: The prevalence of severe asthma was 1.1% in the adult random sample and 9.5% within the asthma sample. Individuals with severe asthma were older and had more symptoms, activity limitations, heart disease and blood neutrophils compared to those with other asthma. They also had lower lung function and despite these impairments, 32% did not have annual contact with a healthcare provider.
Conclusion: The prevalence of severe asthma was higher compared to previous studies, and many individuals with severe asthma did not have regular contact with healthcare providers. Due to the high burden of symptoms and impairments for individuals with severe asthma, it is important that the healthcare system implement strategies to improve follow-up and evaluate these patients according to existing guidelines.

Keywords: asthma epidemiology, asthma control, asthma-medication, asthma severity symptoms, lung function


中文翻译：

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一般人群研究中的严重哮喘：患病率和临床特征

目的：目前的指南主要使用药物水平来区分严重哮喘和其他类型的哮喘。此外，严重哮喘也必须在高强度治疗时无法得到控制，或者如果治疗水平降低则变得无法控制。迄今为止，只有少数研究使用这一定义来调查基于人群的样本中严重哮喘的患病率和临床特征。因此，本研究的目的是评估以人群为代表的西瑞典哮喘研究中重度哮喘患者的患病率和临床特征。
材料和方法：在这项基于人群的横断面研究中，随机选择的样本（n = 1172）和单独的哮喘样本（n = 744）接受了临床检查，完成了结构化访谈并回答了问卷。严重哮喘被定义为尽管按照全球哮喘倡议 (GINA) 步骤 4/5 进行治疗，但哮喘仍不受控制的至少一个特征。该治疗水平需要最低中等剂量的吸入皮质类固醇（ICS）加上第二个控制器或口服皮质类固醇。
结果：成人随机样本中重度哮喘的患病率为 1.1%，哮喘样本中的重度哮喘患病率为 9.5%。与其他哮喘患者相比，患有严重哮喘的患者年龄更大，症状、活动受限、心脏病和血液中性粒细胞更多。他们的肺功能也较低，尽管存在这些障碍，但 32% 的人每年都没有与医疗保健提供者联系。
结论：与之前的研究相比，严重哮喘的患病率较高，并且许多患有严重哮喘的人没有定期与医疗保健提供者联系。由于严重哮喘患者的症状和损伤负担较重，因此医疗保健系统根据现有指南实施改善随访和评估这些患者的策略非常重要。

关键词：哮喘流行病学、哮喘控制、哮喘药物、哮喘严重症状、肺功能