BACKGROUND Health-related quality of life (HRQL) is impaired in patients with idiopathic pulmonary fibrosis (IPF). The King's Brief Interstitial Lung Disease questionnaire (K-BILD) is a validated measure of HRQL, but no previous studies have focused on the validity of K-BILD in IPF. Moreover, the relationship between K-BILD and dyspnoea or the 6-min walk test (6MWT) has not been assessed. The aim of this study was to validate K-BILD in the largest cohort of patients with IPF to date and assess how K-BILD correlates to dyspnoea and 6MWT. METHODS Firstly, K-BILD was translated into Danish using validated translation procedures. Consecutive patients with IPF were recruited. At baseline, patients completed K-BILD, the IPF-specific version of St. Georges Respiratory Questionnaire, University of California, San Diego Shortness of Breath Questionnaire (SOBQ) Short Form-36, and pulmonary function tests and 6MWT were performed. After 14 days, K-BILD and Global Rating of Change Scales were completed. Internal consistency, concurrent validity, test-retest reliability and known groups validity were assessed. Analyses were also performed in subgroups of patients with different time since diagnosis. RESULTS At baseline, 150 patients with IPF completed the questionnaires, and 139 patients completed the questionnaires after 14 days. K-BILD had a high internal consistency (Cronbach's α = 0.92). The concurrent validity was strong compared to SOBQ (r = - 0.66) and moderate compared to 6MWT (r = 0.43). Intraclass correlation coefficients (ICC = 0.91) and a Bland Altman plot demonstrated a good reliability. K-BILD was also able to discriminate between patients with different stages of disease (p < 0.002, Δscore > 7.4) and most results were comparable in patients with different time since diagnosis. CONCLUSION K-BILD is a valid and reliable instrument in patients with IPF and in patients with different time since diagnosis. To a major extent, K-BILD scores reflected the impact of dyspnoea on HRQL and the impact of physical functional capacity measured by the 6MWT to a moderate degree. Compared to PFTs alone, K-BILD provides additional information on the burden of living with IPF, and importantly, K-BILD is simple to implement in both research and clinical contexts. TRIAL REGISTRATION Clinicaltrials.org (NCT02818712) on 30 June 2016.

中文翻译：

---

国王特发性间质性肺疾病问卷在特发性肺纤维化中的验证。

背景技术患有特发性肺纤维化（IPF）的患者的健康相关生活质量（HRQL）受损。国王简明性间质性肺疾病问卷（K-BILD）是一种有效的HRQL量度，但以前没有研究集中在IPF中K-BILD的有效性。此外，尚未评估K-BILD与呼吸困难或6分钟步行测试（6MWT）之间的关系。这项研究的目的是在迄今为止最大的IPF患者队列中验证K-BILD，并评估K-BILD与呼吸困难和6MWT的相关性。方法首先，使用经过验证的翻译程序将K-BILD翻译成丹麦语。招募了连续的IPF患者。在基线时，患者完成了K-BILD，这是IPF特定版本的St. Georges呼吸问卷，加利福尼亚大学，圣地亚哥呼吸短问卷（SOBQ）简短表格36，并进行了肺功能测试和6MWT。14天后，完成了K-BILD和全球变更量表评分。评估内部一致性，并发效度，重测信度和已知组效度。自诊断以来，在不同时间的患者亚组中也进行了分析。结果基线时，有150例IPF患者完成了问卷，而139例患者在14天后完成了问卷。K-BILD具有很高的内部一致性（Cronbach'sα= 0.92）。与SOBQ相比，并发有效性强（r =-0.66），与6MWT相比，并发有效性中等（r = 0.43）。类内相关系数（ICC = 0.91）和Bland Altman图显示出良好的可靠性。K-BILD还能够区分不同疾病阶段的患者（p <0.002，Δscore> 7.4），并且自诊断以来在不同时间的患者中，大多数结果具有可比性。结论K-BILD是IPF患者以及诊断以来不同时间的患者的有效且可靠的仪器。K-BILD评分在很大程度上反映了呼吸困难对HRQL的影响以及6MWT测得的身体功能能力的影响。与单独的PFT相比，K-BILD提供了更多有关IPF负担的信息，重要的是，K-BILD在研究和临床环境中都易于实施。试验注册Clinicaltrials.org（NCT02818712）于2016年6月30日。4），大多数结果与诊断后不同时间的患者具有可比性。结论K-BILD是IPF患者以及诊断后不同时间的患者的有效且可靠的仪器。K-BILD评分在很大程度上反映了呼吸困难对HRQL的影响以及6MWT测得的身体功能能力的影响。与单独的PFT相比，K-BILD提供了更多有关IPF负担的信息，重要的是，K-BILD在研究和临床环境中都易于实施。试验注册Clinicaltrials.org（NCT02818712）于2016年6月30日。4），大多数结果与诊断后不同时间的患者具有可比性。结论K-BILD是IPF患者以及诊断以来不同时间的患者的有效且可靠的仪器。K-BILD评分在很大程度上反映了呼吸困难对HRQL的影响以及6MWT测得的身体功能能力的影响。与单独的PFT相比，K-BILD提供了更多有关IPF负担的信息，重要的是，K-BILD在研究和临床环境中都易于实施。试验注册Clinicaltrials.org（NCT02818712）于2016年6月30日。K-BILD评分在中等程度上反映了呼吸困难对HRQL的影响以及6MWT测得的身体功能的影响。与单独的PFT相比，K-BILD提供了更多有关IPF负担的信息，重要的是，K-BILD在研究和临床环境中都易于实施。试验注册Clinicaltrials.org（NCT02818712）于2016年6月30日。K-BILD评分在中等程度上反映了呼吸困难对HRQL的影响以及6MWT测得的身体功能的影响。与单独的PFT相比，K-BILD提供了更多有关IPF负担的信息，重要的是，K-BILD在研究和临床环境中都易于实施。试验注册Clinicaltrials.org（NCT02818712）于2016年6月30日。