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

描述（由研究者提供）：预防慢性阻塞性肺疾病（COPD）急性加重是延长COPD患者生产生活的最重要方法，已知对呼吸道感染的快速反应可降低急性加重的严重程度。至少有两种环境暴露也可能引发病情加重-烟草烟雾（主动吸烟和被动吸烟）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。对哮喘、支气管高反应性和肺功能急性丧失的研究报告了常见的大量室内呼吸道毒素，包括刺激物，其影响与城市空气污染报告的影响相似，如果不是更强的话。我们假设，减少暴露于与哮喘和其他急性呼吸系统影响相关的药物也可能降低COPD患者的急性加重频率。 本初步研究将使用病例交叉设计，通过将急性加重前几天的触发环境暴露与受试者未发生急性加重时随机选择的周内的暴露进行比较，确定这些暴露。由于尚未确定用于此目的的经过验证的调查工具，我们将开发一份由采访者管理的调查问卷，以收集前一周有关呼吸道刺激物和颗粒物暴露以及家庭、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提出问题，评估是否遇到感兴趣的风险或产生风险的活动以及发生的频率。 研究人群将是入组大型健康维护组织疾病管理组的200例COPD患者。人群将随访1年。我们预计，平均而言，我们将为200名参与者中的每名参与者收集1次急性加重和3个参考期的数据。指导COPD患者在注意到病情加重时给护士打电话。电话采访将在这些时间进行，以及在一年中至少3个其他随机时间。将由经过培训的临床医生使用标准标准（考虑体征和症状的严重程度增加以及药物使用的变化）对急性加重进行临床确认。这次调查将收集有关呼吸道症状和在家庭、社区和工作场所暴露的数据，包括主动吸烟和被动吸烟。这项试点研究将确定支持未来研究的证据，对特定化学制剂进行定量暴露评估。这项拟议的研究将是第一个使用强大的病例交叉设计来识别COPD急性加重的环境触发因素，可能导致预防这种严重和致残性疾病的重要新策略。 公共卫生相关性：我们假设，在家庭、社区和工作场所与哮喘和其他急性呼吸系统影响相关的空气污染物可能会引发COPD恶化。拟议的研究将研究COPD疾病管理组的成员，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发生急性加重的周内的暴露进行比较，来确定临床确认急性加重前几天的触发环境暴露。这项拟议的研究将是第一个使用强大的病例交叉设计来识别COPD急性加重的环境触发因素，可能导致预防这种严重和致残性疾病的重要新策略。

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.