Objective  To study the risk factors of developing progressive pulmonary fibrosis (PPF) within one year in patients diagnosed with rheumatoid arthritis-associated interstitial lung disease (RA-ILD), and develop a nomogram. Methods  A retrospective study was conducted in 145 cases of RA-ILD patients diagnosed and followed up in the Affiliated Hospital of Qingdao University from January 2010 to October 2022. Among them, 106 patients and 39 patients were randomly assigned to a training group and a verification group. The independent predictors of PPF in patients with RA-ILD within one year were determined by univariate and multivariate logistic regression analysis. Then a nomogram is established through these independent predictive variables. Calibration curve, Hosmer-Lemeshow test, receiver operating characteristic (ROC) curve and area under ROC curve (AUC) and clinical decision curve were used to evaluate the predictive efficiency of the nomogram model for PPF in RA-ILD patients within one year. Finally, internal validation was used to test the stability of the model. Results  Of the 145 patients with RA-ILD, 62 (42.76%) developed PPF within one year, including 40 (37.7%) in the training group and 22 (56.41%) in the verification group. The PPF patients had higher proportion of subpleural abnormalities, higher visual score of fibrosis and shorter duration of RA. Logistic regression analysis showed that the duration of rheumatoid arthritis (RA), visual score of fibrosis and subpleural abnormality were independent risk factors for the occurrence of PPF within one year after diagnosis of RA-ILD. A nomogram was constructed based on these independent risk factors. The AUC values of the training group and the verification group were 0.798 (95%CI 0.713 - 0.882) and 0.822 (95%CI 0.678 - 0.967) respectively, indicating that the model had a good ability to distinguish. The clinical decision curve showed that the clinical benefit of PPF risk prediction model was greater when the risk threshold was between 0.06 and 0.71. Conclusion  According to the duration of RA, the visual score of fibrosis and the presence of subpleural abnormalities, the predictive model of PPF was drawn to provide reference for the clinical prediction of PPF in patients with RA-ILD within one year after diagnosis.

Citation： WANG Meihua, YU Wencheng. A clinical model for prediction of progressive pulmonary fibrosis risk within one year in patients with rheumatoid arthritis-associated interstitial lung disease. Chinese Journal of Respiratory and Critical Care Medicine, 2023, 22(4): 237-244. doi: 10.7507/1671-6205.202303012 Copy