Development of a Prediction Model for Acute Exacerbation in Idiopathic Pulmonary Fibrosis: A Study of the Korea IPF Cohort Registry

Background: Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) has the most disastrous impact on prognosis as a major cause of morbidity and mortality. However, there is no proven treatment, and the occurrence of AE is unpredictable. This study aimed to develop a prediction model for AE in patients with IPF using the nationwide Korea IPF Cohort (KICO) registry. Methods: This is a retrospective study of Korean patients with IPF who were enrolled from June 2016 to February 2022 in the KICO registry. We developed a prediction model for AE based on risk factors found in the multivariable logistic regression model. Results: Of 678 patients with IPF, the mean age was 69.4 years, and 82.0% were male. AE occurred in 165 patients (24.3%) during follow-up (median: 40.7 months). The median time from IPF diagnosis to AE was 11.6 (interquartile range: 3.6–23.5) months. Lower forced vital capacity (FVC), shorter six-minute walking distance (6MWD), and the use of home oxygen were independently associated with AE in the multivariable logistic analysis. In a risk-predicting model using variables of FVC, 6MWD, and the use of home oxygen, there was a significant predictive power for AE in both score (area under the curve [AUC], 0.746; 95% confidence interval [CI], 0.705–0.783; P < 0.001) and stage (AUC, 0.696; 95% CI, 0.654–0.736; P < 0.001). Conclusion: Our results suggest that a model using FVC, 6MWD, and home oxygen use may be useful in predicting AE in patients with IPF.