BIOMEDICAL RESEARCH

COPD研究（SPIROMICS）的亚群和中间结局指标：急性加重亚研究：急性加重亚研究有助于SPIROMICS的两个主要目标：1)COPD同质亚组的鉴定；2)用作临床试验终点的中间生物学和临床结局指标。急性加重被认为是COPD自然病程中的前哨事件。其发生频率和严重程度与多种负面影响相关，包括健康状况恶化、肺功能恶化、护理费用增加和死亡率增加。更好地了解这些事件的性质及其症状表现有可能导致对恶化的生物学成因的更好理解，并提供新的治疗方法。

SubPopulations and InteRmediate Outcome Measures In COPD Study (SPIROMICS): Exacerbation substudy ¿ The Exacerbation Substudy contributes to the two primary aims of SPIROMICS the identification of 1) homogeneous subgroups of COPD and 2) intermediate biological and clinical outcome measures for use as clinical trial endpoints. Exacerbations are considered sentinel events in the natural history of COPD. Their frequency and severity have been associated with multiple negative implications including worsening health status, worsening pulmonary function, increasing cost of care, and increased mortality. A better understanding of the nature of these events and their symptomatic manifestations has the potential of leading to an improved understanding of the biological genesis of exacerbations and provide novel therapeutic approaches. Participants who consented to being contacted about participating in additional substudies will be approached during Baseline or clinic Visit 2 to determine interest in the Exacerbation Substudy. Interested participants will then be screened and consented for the substudy. A total of 400 participants will be enrolled in Wave 1 and 2. While each contractor is expected to enroll approximately 67 subjects, the underlining goal is to enroll 400 participants. Negotiations are based on each site recruiting 67 participants. Recruitment adjustments may occur in subsequent periods if it is determined that one site is able to exceed the recruitment goal of 67 while other sites are not. Participants enrolled into the Exacerbation Substudy will fall into one of two substrata: 1) Sub-stratum one (COPD patients at risk for acute exacerbation) ¿ History of two or more exacerbations in the last 12 months 2) Sub-stratum two (COPD patients not at risk for acute exacerbation) ¿ History of one or no exacerbations in the last 12 months Assessments included in this substudy do not require the full cohort in order to achieve the appropriate statistical power.