Department of Medicine and.
Department of Medicine, St. Martinus University, Willemstad, Curaçao, Netherlands Antilles.
Ann Am Thorac Soc. 2023 Dec;20(12):1726-1734. doi: 10.1513/AnnalsATS.202303-208OC.
Hypoxemia in fibrotic interstitial lung disease (ILD) indicates disease progression and is of prognostic significance. The onset of hypoxemia signifies disease progression and predicts mortality in fibrotic ILD. Accurately predicting new-onset exertional and resting hypoxemia prompts appropriate patient discussion and timely consideration of home oxygen. We derived and externally validated a risk prediction tool for both new-onset exertional and new-onset resting hypoxemia. This study used ILD registries from Canada for the derivation cohort and from Australia and the United States for the validation cohort. New-onset exertional and resting hypoxemia were defined as nadir oxyhemoglobin saturation < 88% during 6-minute-walk tests, resting oxyhemoglobin saturation < 88%, or the initiation of ambulatory or continuous oxygen. Candidate predictors included patient demographics, ILD subtypes, and pulmonary function. Time-varying Cox regression was used to identify the top-performing prediction model according to Akaike information criterion and clinical usability. Model performance was assessed using Harrell's C-index and goodness-of-fit (GoF) likelihood ratio test. A categorized risk prediction tool was developed. The best-performing prediction model for both new-onset exertional and new-onset resting hypoxemia included age, body mass index, a diagnosis of idiopathic pulmonary fibrosis, and percent predicted forced vital capacity and diffusing capacity of carbon monoxide. The risk prediction tool exhibited good performance for exertional hypoxemia (C-index, 0.70; GoF, = 0.85) and resting hypoxemia (C-index, 0.77; GoF, = 0.27) in the derivation cohort, with similar performance in the validation cohort except calibration for resting hypoxemia (GoF, = 0.001). This clinically applicable risk prediction tool predicted new-onset exertional and resting hypoxemia at 6 months in the derivation cohort and a diverse validation cohort. Suboptimal GoF in the validation cohort likely reflected overestimation of hypoxemia risk and indicated that the model is not flawed because of underestimation of hypoxemia.
在纤维化间质性肺疾病（ILD）中，低氧血症表明疾病进展，具有预后意义。低氧血症的发生标志着疾病的进展，并预测纤维化ILD 的死亡率。准确预测新发运动性和静息性低氧血症可促使患者进行适当的讨论，并及时考虑家庭吸氧。我们为新发运动性和新发静息性低氧血症分别开发了一种风险预测工具，并进行了外部验证。本研究的推导队列来自加拿大的ILD 登记处，验证队列来自澳大利亚和美国。新发运动性和新发静息性低氧血症定义为 6 分钟步行试验中最低血氧饱和度<88%，静息血氧饱和度<88%，或开始使用便携式或持续吸氧。候选预测因素包括患者人口统计学特征、ILD 亚型和肺功能。时间变化的 Cox 回归用于根据赤池信息量准则和临床可用性确定表现最佳的预测模型。使用 Harrell 的 C 指数和拟合优度（GoF）似然比检验评估模型性能。开发了一种分类风险预测工具。用于预测新发运动性和新发静息性低氧血症的最佳预测模型包括年龄、体重指数、特发性肺纤维化诊断以及预计用力肺活量和一氧化碳弥散量的百分比。该风险预测工具在推导队列中对运动性低氧血症（C 指数，0.70；GoF， = 0.85）和静息性低氧血症（C 指数，0.77；GoF， = 0.27）具有良好的性能，在验证队列中除静息性低氧血症的校准外（GoF， = 0.001）具有相似的性能。该具有临床应用价值的风险预测工具可预测推导队列中 6 个月内新发运动性和静息性低氧血症，以及不同验证队列中。验证队列中较差的 GoF 可能反映了低氧血症风险的高估，并表明该模型不是因为低氧血症的低估而存在缺陷。
