BACKGROUND Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial pneumonia with an unpredictable course. The aims of this study were to retrospectively re-evaluate a cohort of patients with IPF according to the 2011 international IPF guidelines and 1) to characterize the subgroups of patients when classified according to their observed survival times and 2) to evaluate whether Composite Physiologic Index (CPI), Gender-Age-Physiology (GAP) Index or clinical variables could predict mortality. METHODS Retrospective data was collected and patients were classified into subgroups according to their observed lifespans. Differences in clinical variables, CPI and GAP stages as well as in comorbidities were investigated between the subgroups. Predictors of mortality were identified by COX proportional hazard analyses. RESULTS A total of 132 patients were included in this study. The disease course was rapid (≤ 2 years) in 30.0%, moderate (2-5 years) in 28.0% and slow (≥ 5 years) in 29.0% of the patients. Pulmonary function tests (PFT) and CPI at baseline differentiated significantly between the rapid disease course group and those patients with longer survival times. However, the predictive accuracy of the investigated clinical variables was mainly less than 0.80. The proportions of patients with comorbidities did not differ between the subgroups, but more patients with a rapid disease course were diagnosed with heart failure after the diagnosis of IPF. Most patients with a rapid disease course were categorized in GAP stages I and II, but all patients in GAP stage III had a rapid disease course. The best predictive multivariable model included age, gender and CPI. GAP staging had slightly better accuracy (0.67) than CPI (0.64) in predicting 2-year mortality. CONCLUSIONS Although the patients with a rapid disease course could be differentiated at baseline in terms of PFT and CPI, the predictive accuracy of any single clinical variable as well as CPI and GAP remained low. GAP staging was unable to identify the majority of patients with a rapid disease progression. It is challenging to predict disease progression and mortality in IPF even with risk prediction models.

中文翻译：

---

特发性肺纤维化疾病进展亚组的比较。

背景技术特发性肺纤维化（IPF）是一种进展性间质性肺炎，其病程不可预测。这项研究的目的是根据2011年国际IPF指南回顾性重新评估一组IPF患者； 1）根据观察到的生存时间对患者亚组进行表征，以及2）评估复合生理指标是否（CPI），性别年龄生理学（GAP）指数或临床变量可以预测死亡率。方法收集回顾性数据，根据患者观察到的寿命将其分为亚组。在亚组之间研究了临床变量，CPI和GAP分期以及合并症的差异。通过COX比例风险分析确定死亡率的预测指标。结果本研究共纳入132例患者。病程为快速（≤2年）的患者为30.0％，中度（2-5年）的患者为28.0％，缓慢（≥5年）的患者为29.0％。在快速病程组和生存期较长的患者之间，基线时的肺功能测试（PFT）和CPI有显着差异。但是，研究的临床变量的预测准确性主要低于0.80。在亚组之间，合并症患者的比例没有差异，但是在IPF诊断之后，更多患有快速病程的患者被诊断出患有心力衰竭。大多数具有快速疾病进程的患者被归为第一和第二阶段的GAP，但是所有处于第三阶段GAP的患者都具有快速疾病的进程。最好的预测性多变量模型包括年龄，性别和CPI。在预测2年死亡率时，GAP分期的准确性（0.67）略高于CPI（0.64）。结论尽管可以在基线时根据PFT和CPI区分快速病程的患者，但是任何单个临床变量以及CPI和GAP的预测准确性仍然很低。GAP分期无法确定大多数疾病进展迅速的患者。即使使用风险预测模型来预测IPF中的疾病进展和死亡率也是具有挑战性的。GAP分期无法确定大多数疾病进展迅速的患者。即使使用风险预测模型来预测IPF中的疾病进展和死亡率也是具有挑战性的。GAP分期无法确定大多数疾病进展迅速的患者。即使使用风险预测模型来预测IPF中的疾病进展和死亡率也是具有挑战性的。