A NEW analysis of two major idiopathic pulmonary fibrosis trials has produced a practical 6-minute walk test prediction score that more accurately identifies patients at risk of death or respiratory hospitalisation.
A Pragmatic Approach to the 6-Minute Walk Test Prediction Score
The 6-minute walk test is widely used to assess functional capacity in people with interstitial lung disease, yet clinicians often rely on single parameters that offer only partial insight into prognosis. To improve risk assessment, investigators pooled data from the ISABELA trials, large, randomised studies evaluating treatments for idiopathic pulmonary fibrosis that employed a tightly standardised walking test protocol. The aim was to combine multiple elements of the assessment into an easy-to-use 6-minute walk test prediction score capable of forecasting clinically meaningful outcomes.
ODDS Model Integrates Four Key Predictors
Among 1,251 participants in the derivation dataset, researchers identified four test components independently associated with time to respiratory hospitalisation or death: the Borg dyspnoea score, the oxygen flow rate needed during the test, the lowest oxygen saturation reached, and the total distance walked. These variables were combined to create a composite tool known as the ODDS model: oxygen, distance, dyspnoea and saturation.
When tested against real outcomes at 12, 24, and 48 weeks, the 6-minute walk test prediction score outperformed any single measure, with area under the curve values of 0.797, 0.781, and 0.766 respectively. Performance remained robust in an external validation cohort of 295 individuals, showing an area under the curve of 0.758 at 48 weeks.
Clinical and Research Applications for Idiopathic Pulmonary Fibrosis
The authors highlight that the 6-minute walk test prediction score offers a more holistic interpretation of functional testing in idiopathic pulmonary fibrosis. Because the tool incorporates symptoms, oxygen requirement, physiological response and exercise capacity, it may better distinguish higher-risk patients in routine care. The model could also support patient stratification in future clinical trials, improving study design and enabling more targeted monitoring of disease progression.
Reference
Nathan SD et al. Development and validation of a predictive 6-min walk score in patients with idiopathic pulmonary fibrosis. Eur Respir J. 2025;66(5):2402565.
