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.
Objective To clarify the specific clinical predictive efficacy of CT and serological indicators for the progression of connective tissue disease-associated interstitial lung disease (CTD-ILD) to progressive pulmonary fibrosis (PPF). Methods Patients who were diagnosed with CTD-ILD in Chest Hospital of Zhengzhou University Between January 2020 and December 2021 were recruited in the study. Clinical data and high-resolution CT results of the patients were collected. The patients were divided into a stable group and a progressive group (PPF group) based on whether PPF occurred during follow-up. COX proportional hazards regression was used to identify risk factors affecting the progression of CTD-ILD to PPF, and a risk prediction model was established based on the results of the COX regression model. The predictive efficacy of the model was evaluated through internal cross-validation. Results A total of 194 patients diagnosed with CTD-ILD were enrolled based on the inclusion and exclusion criteria. Among them, 34 patients progressed to PPF during treatment, and 160 patients did not progress. The variables obtained at lambda$1se in LASSO regression were ANCA associated vasculitis, lymphocytes, albumin, erythrocyte sedimentation rate, and serum ferritin. Multivariate COX regression analysis showed that the extent of fibrosis, serum ferritin, albumin, and age were independent risk factors for the progression of CTD-ILD to PPF (all P<0.05). A prediction model was established based on the results of the multivariate COX regression analysis. The area under the receiver operator characteristic curve at 6 months, 9 months, and 12 months was 0.989, 0.931, and 0.797, respectively, indicating that the model has good discrimination and sensitivity, and good predictive efficacy. The calibration curve showed a good overlap between predicted and actual values. Conclusions The extent of fibrosis, serum ferritin, albumin, and age are independent risk factors for the progression of CTD-ILD to PPF. The model established based on this and externally validated shows good predictive efficacy.