A Systematic Review of Mortality Risk Prediction Models for Idiopathic Pulmonary Fibrosis

Aims/Background Idiopathic pulmonary fibrosis (IPF) is associated with an increased mortality risk. However, the factors that contribute to this risk remain unknown. This study aimed to systematically review existing predictive models for IPF-related mortality and to evaluate prognostic factors associated with patient outcomes. Methods A comprehensive literature search was conducted on PubMed, Cochrane Library, Web of Science, and Embase for studies on IPF mortality risk prediction models published between 1 January 1984 and 15 November 2024. Two independent reviewers screened, extracted, and cross-checked the data. The risk of bias and model applicability were also evaluated. Results A total of 17 risk prediction models were identified. The area under the receiver operating characteristic (ROC) curve (AUC) ranged from 0.728 to 0.907, while the model validation results ranged from 0.750 to 0.920. The concordance index (C-index) of 10 studies was more than 0.7, indicating good predictive performance. This study encompassed a total of 17 risk prediction models incorporating between 3 and 8 combined prognostic variables, with the most frequently included predictors being forced vital capacity as a percentage of the predicted value (FVC%pred), carbon monoxide diffusion capacity as a percentage of the predicted value (DLCO%pred), gender, age, six-minute walk test (6MWT) results, and dyspnea severity. Conclusion Current IPF mortality risk prediction models remain in an exploratory phase, with a generally high risk of bias. Furthermore, the lack of external validation in some models limits their generalizability. Future research should focus on improving the applicability of the model to enhance clinical application.