Background Lung function testing remains a cornerstone in the assessment and management of interstitial lung disease (ILD) patients. The clinical implications of the Global Lung function Initiative (GLI) reference equations and the updated interpretation strategies remain uncertain. Methods Adult patients with ILD with baseline forced vital capacity (FVC) were included from the Australasian ILD registry and the National Healthcare Group ILD registry, Singapore. The European Coal and Steel Community and Miller reference equations were compared with the GLI reference equations to assess (a) differences in lung function percent predicted values; (b) ILD risk prediction models and (c) eligibility for ILD clinical trial enrolment. Results Among 2219 patients with ILD, 1712 (77.2%) were white individuals. Idiopathic pulmonary fibrosis (IPF), connective tissue disease-associated ILD and unclassifiable ILD predominated. Median FVC was 2.60 (2.01–3.36) L, forced expiratory volume in 1 s was 2.09 (1.67–2.66) L and diffusing capacity of the lungs for carbon monoxide (DLCO) was 13.60 (10.16–17.60) mL/min/mm Hg. When applying the GLI reference equations, the mean FVC percentage predicted was 8.8% lower (87.7% vs 78.9%, p<0.01) while the mean DLCO percentage predicted was 4.9% higher (58.5% vs 63.4%, p<0.01). There was a decrease in 19 IPF and 119 non-IPF patients who qualified for the nintedanib clinical trials when the GLI reference equations were applied. Risk prediction models performed similarly in predicting mortality using both reference equations. Conclusion Applying the GLI reference equations in patients with ILD leads to higher DLCO percentage predicted values and smaller lung volume percentage predicted values. While applying the GLI reference equations did not impact on prognostication, fewer patients met the clinical trial criteria for antifibrotic agents. Data are available on reasonable request.

中文翻译：

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2022 年肺功能更新和 GLI 全局参考方程对间质性肺病患者的影响


背景 肺功能检测仍然是间质性肺病 （ILD） 患者评估和管理的基石。全球肺功能倡议 （GLI） 参考方程和更新的解释策略的临床意义仍不确定。方法 从澳大利亚 ILD 登记处和新加坡国家医疗保健集团 ILD 登记处纳入具有基线用力肺活量 （FVC） 的成年 ILD 患者。将欧洲煤钢共同体和 Miller 参考方程与 GLI 参考方程进行比较，以评估 （a） 肺功能百分比预测值的差异;（b） ILD 风险预测模型和 （c） ILD 临床试验入组资格。结果 在 2219 例 ILD 患者中，1712 例 （77.2%） 为白人个体。特发性肺纤维化 （IPF） 、结缔组织病相关 ILD 和无法分类的 ILD 占主导地位。中位 FVC 为 2.60 （2.01-3.36） L，1 s 用力呼气容积为 2.09 （1.67-2.66） L，肺一氧化碳弥散量 （DLCO） 为 13.60 （10.16-17.60） mL/min/mm Hg。当应用 GLI 参考方程时，预测的平均 FVC 百分比低 8.8%（87.7% 对 78.9%，p<0.01），而预测的平均 DLCO 百分比高 4.9%（58.5% 对 63.4%，p<0.01）。当应用 GLI 参考方程时，符合尼达尼布临床试验条件的 19 名 IPF 患者和 119 名非 IPF 患者有所减少。风险预测模型在使用两个参考方程预测死亡率时的表现相似。结论 在 ILD 患者中应用 GLI 参考方程会导致较高的 DLCO 百分比预测值和较小的肺体积百分比预测值。 虽然应用 GLI 参考方程对预后没有影响，但符合抗纤维化药物临床试验标准的患者较少。数据可应合理要求提供。