Home and community exposures in COPD exacerbation: A pilot case cross-over study

描述(由研究人员提供)：预防慢性阻塞性肺疾病(COPD)的恶化是延长COPD患者生产寿命的最重要方法，众所周知，对呼吸道感染的快速反应可以减轻恶化的严重程度。至少两种环境暴露也可能引发恶化--烟草烟雾(主动和被动吸烟)和城市空气污染。除此之外，人们对家庭、社区和工作中可能加剧COPD的呼吸道刺激物和其他污染物的暴露知之甚少。关于哮喘、支气管高反应性和急性肺功能丧失的研究报告称，室内经常大量暴露于包括刺激物在内的呼吸道毒素，其影响与城市空气污染的报告相似，如果不是更强的话。我们假设，减少与哮喘和其他急性呼吸影响相关的药物的暴露也可能减少COPD患者的恶化频率。这项试点研究将使用病例交叉设计，通过将这些暴露与随机选择的参与者没有经历恶化的几周内的暴露进行比较，确定在病情恶化前几天触发环境暴露的情况。由于尚未为此目的确定有效的调查工具，我们将制定一份面试者管理的问卷，以收集前一周暴露于呼吸道刺激物和颗粒物以及在家庭、社区和工作中产生这些暴露的活动的数据。将从已公布的工具中引出问题，评估是否以及多久一次遇到感兴趣的暴露或产生暴露的活动发生的频率。研究人群将是在一家大型健康维护组织的疾病管理小组登记的200名COPD患者。对人口进行为期一年的跟踪调查。我们预计，平均而言，我们将为200名参与者每人收集1个病情加重和3个参照期的数据。COPD患者被指示在他们注意到病情恶化的时候打电话给护士。电话采访将在这两个时间段以及年内至少3个其他随机时间进行。病情加重将由训练有素的临床医生使用标准标准进行临床确认，标准标准考虑到体征和症状的严重性增加以及药物使用的变化。访谈将收集有关家庭、社区和工作场所的呼吸道症状和暴露的数据，包括主动和被动吸烟。这项初步研究将确定支持未来对特定化学制剂进行定量暴露评估的研究的证据。这项拟议的研究将是第一次使用强大的病例交叉设计来确定COPD恶化的环境触发因素，可能导致预防这种严重和致残性疾病的重要新战略。 公共卫生相关性：我们假设，与家庭、社区和工作场所的哮喘和其他急性呼吸道影响相关的空气污染物可能会引发COPD的恶化。这项拟议的研究将研究COPD疾病管理小组的成员，并使用病例交叉设计，通过将这些暴露与随机选择的患者未经历恶化的几周的暴露进行比较，确定在临床确认的恶化之前的几天内触发环境暴露的情况。这项拟议的研究将是第一次使用强大的病例交叉设计来确定COPD恶化的环境触发因素，可能导致预防这种严重和致残性疾病的重要新战略。

DESCRIPTION (provided by investigator): Preventing chronic obstructive pulmonary disease (COPD) exacerbation is the most important method for prolonging the productive life of COPD patients, and rapid response to respiratory infection is known to reduce the severity of exacerbations. At least 2 environmental exposures may also trigger exacerbations - tobacco smoke (both active and passive smoking) and urban air pollution. Beyond these, little is known about exposures to respiratory irritants and other pollutants in the home, community and work that might exacerbate COPD. Studies of asthma, bronchial hyper reactivity and acute loss of pulmonary function have reported common and substantial indoor exposures to respiratory toxins including irritants, with effects similar to if not stronger than those reported for urban air pollution. We hypothesize that reducing exposure to agents associated with asthma and other acute respiratory effects may also reduce exacerbation frequency in COPD patients. This pilot study will use a case-crossover design to identify triggering environmental exposures in the days immediately preceding an exacerbation by comparing these exposures to those in randomly chosen weeks when participants are not experiencing exacerbations. Because no validated survey instrument has been identified for this purpose, we will develop an interviewer-administered questionnaire to gather data for the previous week on exposures to respiratory irritants and particulates as well as on activities generating these exposures in the home, community and work. Questions will be drawn from published instruments assessing whether and how often the exposures of interest were encountered, or the exposure-generating activities occurred. The study population will be 200 COPD patients enrolled in the disease management group of a large health maintenance organization. The population will be followed for 1 year. We expect that on average we will gather data on 1 exacerbation and 3 referent periods for each of the 200 participants. COPD patients are instructed to phone a nurse whenever they notice the onset of an exacerbation. Telephone interviews will be conducted at these times, as well as at least 3 other random times during the year. Exacerbations will be clinically confirmed by a trained clinician using standard criteria which consider increased severity of signs and symptoms as well as changes in medication usage. The intervew will gather data on respiratory symptoms and exposures in the home, community and work, including both active and passive smoking. This pilot study will identify evidence supporting future research with quantitative exposure assessment of specific chemical agents. The proposed study would be the first to use the powerful case-crossover design to identify environmental triggers of COPD exacerbation, potentially leading to important new strategies for prevention of this severe and disabling disease. PUBLIC HEALTH RELEVANCE: We hypothesize that air pollutants associated with asthma and other acute respiratory effects in the home, community and workplace may trigger exacerbation of COPD. The proposed research will study members of a COPD disease management group, and use a case-crossover design to identify triggering environmental exposures in the days immediately preceding a clinically confirmed exacerbation by comparing these exposures to those in randomly chosen weeks when patients are not experiencing exacerbations. The proposed study would be the first to use the powerful case-crossover design to identify environmental triggers of COPD exacerbation, potentially leading to important new strategies for prevention of this severe and disabling disease.