Recent research led by Steven D. Nathan, MD, has produced an easy-to-use six-minute walk test prediction score that more precisely predicts patients with idiopathic pulmonary fibrosis (IPF) who are at increased risk of respiratory hospitalization or death. Results of the study, “Development and Validation of a Predictive 6-Min Walk Score in Patients With Idiopathic Pulmonary Fibrosis,” were published in the European Medical Journal.
Currently, the six-minute walk test is widely used to evaluate pulmonary function in people with interstitial lung disease (ILD). However, health care professionals often rely on a single parameter, which only offers limited insight into the diagnosis. Investigators sought to improve clinically meaningful outcomes by combining elements to create a more pragmatic assessment.
Researchers analyzed pooled data from 1,251 participants in two major IPF clinical studies — the large-scale, replicate, randomized, controlled ISABELA trials. They identified four key variables independently associated with increased risk of respiratory hospitalization or death:
- Oxygen flow rate required during the six-minute walk test (6MWT)
- Total distance walked
- Borg dyspnea score
- Lowest achieved oxygen saturation
The team combined the predictors to create the ODDS model (oxygen, distance, dyspnea, saturation) and tested it against real-world outcomes at 12, 24 and 48 weeks. The model outperformed results of any single parameter (AUC of 0.797, 0.781 and 0.766, respectively). In an external validation cohort of 295 individuals, results remained robust, with AUC of 0.758 at 48 weeks.
The new composite tool incorporates multiple important predictors, allowing it to more accurately identify high-risk patients, the authors noted.
They said the ODDS model is a more holistic interpretation of pulmonary function, and it could help stratify patients in future clinical trials.
