Development and Validation of a Clinical Scoring System Predicting 30-Day Mortality in Acute Exacerbation of Idiopathic Pulmonary Fibrosis.

Abstract

Background and objectives: Acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) is a frequent and fatal complication of IPF, with highly variable individual outcomes that are challenging to predict.

Methods: This study included patients (≥ 19 years) who met the diagnostic criteria for AE-IPF. The primary outcome was 30-day mortality following hospital admission. Data on commonly assessed parameters at the time of emergency room presentation or hospital admission were collected. Variable selection and scoring were performed using the LASSO method and multivariable logistic regression, and the resulting model was validated in an independent cohort.

Results: The derivation and validation cohorts comprised 128 and 100 patients, respectively. The final model incorporated eight variables (points): age ≥ 69 years (1), smoking status (current smoker: 2, past smoker: 1), use of home oxygen (1), history of hospital admission for non-AE events within the past 6 months (1), body mass index < 18.5 or > 23 kg/m² (1), lymphocyte percentage < 19% (2), total protein < 6.5 g/dL (1) and lactate level ≥ 1.75 mmol/L (1). Patient scores were calculated by summing the points for each variable. This scoring system of total 10 points demonstrated good discrimination, with Harrell's C-statistics of 0.84 (95% confidence interval, 0.75-0.93) in the derivation cohort and 0.81 (95% confidence interval, 0.71-0.92) in the validation cohort, and performed well in predicting 2-week, 3-month and in-hospital mortality.

Conclusion: We developed and validated a scoring system based on readily available clinical parameters that effectively stratified 30-day mortality risk in patients with AE-IPF, offering a practical tool for bedside prognosis.