关键词: 特发性肺纤维化, 性别-年龄-肺功能模型, 复合生理指数, 预后, 预测

Abstract: Background　Gender，age，and physiologic variables（GAP）staging and composite physiologic index（CPI），are often used alone for predicting the death risk of idiopathic pulmonary fibrosis（IPF），but which is more superior or has higher clinical value is still unclear. Objective　To explore the predictive value of GAP staging and CPI for risk of death in patients with IPF. Methods　A retrospective analysis was done in 200 cases of confirmed IPF with complete clinical data and follow-up records who hospitalized in Shanghai Pulmonary Hospital，Tongji University，from 2012 to 2019〔including 181 men（90.5%），and 19 women（9.5%），with an average age of（66.0±7.6）years（ranging from 41 to 85 years）〕. By using GAP staging，109（54.5%），75（37.5%），and 16（8.0%）cases were classified as at GAP stage Ⅰ，stage Ⅱ，and stage Ⅲ，respectively. And by using CPI score，99（49.5%）and 101（50.5%）cases were evaluated with CPI ≤ 41 points，and >41 points，respectively. Clinical，imaging，and physiological characteristics were compared across GAP stages and CPI groups to find the intergroup differences. Cox regression was used to perform univariate analysis of the prognostic factors of IPF. The area under the ROC curve（AUC）of each of the two models to predict the mortality of IPF patients was calculated to measure the prognostic accuracy. Medcalc was used to quantify the predictive accuracy of the two models for overall IPF mortality，and one-year，two-year，and three-year IPF mortality. Results　Cox regression analysis demonstrated that high GAP score〔HR=1.038，95%CI（1.023，1.054）〕，high CPI score〔HR=1.509，95%CI（1.286，1.771）〕，GAP stage Ⅱ〔HR= 2.622，95%CI（1.536，4.475）〕，GAP stage Ⅲ〔HR=4.002，95%CI（1.947，8.226）〕were independently associated with increased risk of poor prognosis of IPF patients（P<0.05）. For predicting one-year，two-year，and three-year mortality as well as overall mortality of IPF patients，the AUC of GAP staging was 0.685〔95%CI（0.616，0.749）〕，0.675〔95%CI（0.606，0.740）〕，0.642〔95%CI（0.571，0.708）〕，and 0.668〔95%CI（0.598，0.733）〕，respectively，and the AUC of CPI score was 0.750〔95%CI（0.684，0.809）〕，0.745〔95%CI（0.679，0.804）〕，0.735〔95%CI（0.669，0.795）〕，0.745〔95%CI（0.679，0.804）〕，respectively. GAP staging and CPI score had statistically significant differences in the AUC for predicting two-year，and three-year mortality as well as overall mortality of IPF（Z=2.193，P=0.028 3；Z=2.918，P=0.003 5；Z=2.529，P=0.011 4），
but had no statistically difference in one-year mortality（Z=1.799，P=0.072 1）. Conclusion　Both CPI and GAP staging may be efficient prognostic factors for IPF. CPI was significantly better than GAP staging in predicting the overall，two-year，and three-year mortality，but the AUC ranged 0.64 to 0.75，indicating that its prognostic performance may be limited. More practical and feasible death risk prediction models are still needed to be established.

Key words: Idiopathic pulmonary fibrosis, Composite physiologic index, GAP stage, Prognosis, Forecasting