RATIONALE Asthma is heterogeneous and knowledge on exacerbation patterns is lacking. Previous studies have had a relatively short follow-up or focused on severe disease. OBJECTIVES To describe exacerbation patterns over a prolonged follow-up in a population that includes patients of all disease severity. METHODS We used electronic health care records to identify patients with asthma aged 18-55 years and their exacerbations from 2007 to 2015. A cohort with greater than or equal to 7 years of data was used to describe exacerbation patterns by asthma severity defined by medication use. Effect estimates for risk factors were calculated for sporadic (single year of exacerbations) and recurrent (>1 yr) exacerbation patterns, using logistic regression. In a nested case-control design, the association between a history of exacerbations, spanning 5 years, and a future exacerbation was examined. MEASUREMENTS AND MAIN RESULTS A total of 51,462 patients were eligible for the 7-year cohort; 64% had no exacerbations. Of those who exacerbated, 51% did so only once; exacerbation frequency increased with disease severity. Only 370 patients (0.7%) were characterized by a frequent-exacerbator phenotype (yearly exacerbations), of whom 58% had mild/moderate asthma. Exacerbation risk factors were not uniquely associated with a particular exacerbation pattern. A past exacerbation increased the risk of a future exacerbation more than all other factors, although this effect dissipated over 5 years. CONCLUSIONS During 7 years of follow-up, exacerbations occur in around one-third of patients. Of those who exacerbate, half do not do so again; the timing of future exacerbations is largely unpredictable. Just 2% exhibit a frequent-exacerbator phenotype. Past exacerbation patterns are the most informative risk factor for predicting future exacerbations.

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英国成人哮喘的恶化模式。基于人群的研究。

基本原理 哮喘是异质的，缺乏关于恶化模式的知识。以前的研究的随访时间相对较短或集中在严重疾病上。目的 描述包括所有疾病严重程度患者在内的人群中长期随访的恶化模式。方法 我们使用电子医疗记录来识别 2007 年至 2015 年 18-55 岁的哮喘患者及其恶化情况。使用具有大于或等于 7 年数据的队列来描述根据药物使用定义的哮喘严重程度的恶化模式. 使用逻辑回归计算散发性（一年的恶化）和复发性（> 1 年）恶化模式的风险因素的影响估计值。在嵌套病例对照设计中，恶化史之间的关联，跨越 5 年，并检查了未来的恶化。测量和主要结果 共有 51,462 名患者符合 7 年队列的条件；64% 没有恶化。在那些恶化的人中，51% 只做了一次；加重频率随疾病严重程度而增加。只有 370 名患者 (0.7%) 具有频繁加重表型（每年加重）的特征，其中 58% 患有轻度/中度哮喘。急性加重风险因素与特定的急性加重模式没有唯一的关联。过去的急性加重比所有其他因素更能增加未来急性加重的风险，尽管这种影响在 5 年内消失。结论 在 7 年的随访中，大约三分之一的患者出现恶化。在那些加剧的人中，有一半不再这样做；未来恶化的时间在很大程度上是不可预测的。只有 2% 的人表现出频繁加重的表型。过去的恶化模式是预测未来恶化的最有用的风险因素。