Background Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrosing interstitial lung disease with a poor prognosis. While there is evidence suggesting that outdoor air pollution affects the clinical course of IPF, the impact of indoor air pollution on patients with IPF has not been extensively studied. Therefore, this prospective multicentre observational study aims to investigate the association between indoor air pollution and clinical outcomes in patients with IPF. Methods and analysis This study enrolled 140 patients with IPF from 12 medical institutes in the Seoul and Metropolitan areas of the Republic of Korea. Over the course of 1 year, participants visited the institutes every 3 months, during which their clinical data and blood samples were collected. Additionally, indoor exposure to particulate matter ≤2.5 µm (PM2.5) was measured using MicroPEM (RTI International, Research Triangle Park, North Carolina, USA) in each participant’s house for 5 days every 3 months. Lung function was assessed using both site spirometry at each institution and portable spirometry at each participant’s house every 3 months. The study will analyse the impact of indoor PM2.5 on clinical outcomes, including mortality, acute exacerbation, changes in lung function and health-related quality of life, in the participants. This study represents the first attempt to evaluate the influence of indoor air pollution on the prognosis of patients with IPF. Ethics and dissemination This study has received approval from the institutional review board of all participating institutions, including Asan Medical Center, Seoul, Republic of Korea (2021-0072). Trial registration number KCT0006217. The data supporting the findings of this study are available upon reasonable request from the corresponding author.

中文翻译：

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室内空气污染对间质性肺病患者临床结果的影响：多中心前瞻性观察研究方案

背景 特发性肺纤维化（IPF）是一种预后不良的慢性进行性纤维化间质性肺疾病。虽然有证据表明室外空气污染影响 IPF 的临床病程，但室内空气污染对 IPF 患者的影响尚未得到广泛研究。因此，这项前瞻性多中心观察性研究旨在调查室内空气污染与 IPF 患者临床结果之间的关联。方法与分析 本研究招募了来自韩国首尔和首都圈 12 家医疗机构的 140 名 IPF 患者。在一年的时间里，参与者每三个月访问一次研究机构，在此期间收集他们的临床数据和血液样本。此外，每 3 个月使用 MicroPEM（RTI International，美国北卡罗来纳州三角研究园）测量每个参与者家中 5 天的室内暴露于≤2.5 µm (PM2.5) 的颗粒物。每 3 个月使用每个机构的现场肺活量计和每个参与者家中的便携式肺活量计对肺功能进行评估。该研究将分析室内 PM2.5 对参与者临床结果的影响，包括死亡率、急性加重、肺功能变化和健康相关生活质量。这项研究首次尝试评估室内空气污染对 IPF 患者预后的影响。伦理与传播 本研究已获得所有参与机构的机构审查委员会的批准，包括韩国首尔峨山医疗中心 (2021-0072)。试用注册号KCT0006217。支持本研究结果的数据可根据通讯作者的合理要求提供。