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）加重是延长COPD患者生产寿命最重要的方法，而对呼吸道感染的快速反应可以降低加重的严重程度。至少有两种环境暴露也可能引发病情恶化——烟草烟雾（主动和被动吸烟）和城市空气污染。除此之外，人们对在家庭、社区和工作中暴露于可能加剧慢性阻塞性肺病的呼吸刺激物和其他污染物知之甚少。关于哮喘、支气管高反应性和急性肺功能丧失的研究报告了常见和大量的室内呼吸毒素暴露，包括刺激物，其影响与所报告的城市空气污染相似，甚至更强。我们假设，减少与哮喘和其他急性呼吸系统影响相关的物质暴露也可能降低COPD患者的恶化频率。该试点研究将采用病例交叉设计，通过将这些暴露与随机选择的参与者未经历恶化的几周内的暴露进行比较，确定在恶化前几天的触发环境暴露。由于没有为此目的确定有效的调查工具，我们将制定一份由访谈者管理的问卷，以收集前一周接触呼吸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。将从已发表的文书中提出问题，评估是否和多久遇到一次有关的暴露，或发生了产生暴露的活动。研究人群将是一家大型健康维护组织疾病管理组的200名COPD患者。该人群将被跟踪1年。我们预计，平均而言，我们将为200名参与者每人收集1次恶化和3个参考时期的数据。慢性阻塞性肺病患者被告知，当他们发现病情开始恶化时，就打电话给护士。在这些时间，以及年内至少3次其他随机时间，将进行电话采访。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，标准标准考虑体征和症状的严重程度增加以及药物使用的变化。访谈将收集有关家庭、社区和工作中呼吸系统症状和暴露的数据，包括主动和被动吸烟。这项试点研究将确定证据，支持未来对特定化学制剂进行定量暴露评估的研究。这项拟议的研究将首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，可能为预防这种严重和致残疾病提供重要的新策略。

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.