Department of Respiratory Medicine and Allergy, Tosei General Hospital, Seto, Japan.
Center for Advanced Medicine and Clinical Research, Nagoya University Hospital, Nagoya, Japan.
Respirology. 2017 Nov;22(8):1609-1614. doi: 10.1111/resp.13138. Epub 2017 Aug 8.
In Japan, the classification of disease severity of idiopathic pulmonary fibrosis (IPF) (J-system) has been used in making decisions on medical care subsidies. The present J-system consists of arterial partial pressure of oxygen (PaO ) and exercise desaturation in stages of I-IV. It provides a good prognostic classification in stages III and IV, but not in stages I and II. Therefore, we propose a revised system to improve discriminative ability in stages I and II.
We compared the revised J-system with the present J-system using Cox proportional hazards model to predict mortality rate. We also evaluated the recently proposed GAP (Gender, Age and Physiology) system in comparison to both J-systems.
Two-hundred and fifteen IPF patients were studied retrospectively. A univariate model showed that the present and revised J-systems and a modified GAP system were all significant prognostic factors. The C-statistic for discriminating prognosis was higher in the revised J-system than the modified GAP system and the present J-system (0.677, 0.652 and 0.659, respectively). The C-statistics of these models produced from the 10 000 bootstrap samples were similar to those of the original models, suggesting good internal validation (0.665 (95% CI: 0.621-0.705), 0.645 (0.600-0.686) and 0.659 (0.616-0.700), respectively). Multivariate analysis revealed that the revised J-system (P = 0.0038) and the modified GAP system (P = 0.0029) were independent prognostic factors.
The revised J-system can provide a better mortality prediction than the present one. Both the revised J-system and the modified GAP system are independent and valuable tools for prognostication and clinical management for IPF.
在日本，特发性肺纤维化（IPF）的疾病严重程度分类（J 系统）被用于医疗补助决策。目前的 J 系统由动脉血氧分压（PaO ）和 I-IV 期运动性血氧饱和度下降组成。它在 III 和 IV 期提供了良好的预后分类，但在 I 和 II 期则不然。因此，我们提出了一个修订的系统，以提高 I 和 II 期的鉴别能力。
我们使用 Cox 比例风险模型比较了修订后的 J 系统和现行 J 系统，以预测死亡率。我们还比较了最近提出的 GAP（性别、年龄和生理学）系统与两个 J 系统的预测能力。
回顾性研究了 215 例 IPF 患者。单变量模型显示，现行和修订后的 J 系统和改良的 GAP 系统都是重要的预后因素。修订后的 J 系统在预测预后方面的 C 统计量高于改良的 GAP 系统和现行 J 系统（分别为 0.677、0.652 和 0.659）。来自 10000 个 bootstrap 样本的这些模型的 C 统计量与原始模型相似，表明内部验证良好（分别为 0.665（95%CI：0.621-0.705）、0.645（0.600-0.686）和 0.659（0.616-0.700））。多变量分析显示，修订后的 J 系统（P=0.0038）和改良的 GAP 系统（P=0.0029）是独立的预后因素。
修订后的 J 系统可以提供比现行系统更好的死亡率预测。修订后的 J 系统和改良的 GAP 系统都是独立的、有价值的 IPF 预后和临床管理工具。
