Step Count Thresholds to Predict All-Cause Mortality in Idiopathic Pulmonary Fibrosis

idiopathic pulmonary fibrosis, lung scan
Can a certain level of daily physical activity improve the prognosis for patients with idiopathic pulmonary fibrosis?

Step count was a significant predictor of all-cause mortality in idiopathic pulmonary fibrosis (IPF), with patients above the cutoff point of 3473 steps seeing a decrease in mortality by more than half, according to the results of a recent study published in the journal Respiration.

The current study investigated the prognostic significance of physical activity, as assessed by step count. To measure physical activity in patients with idiopathic pulmonary fibrosis, investigators recorded study participants’ steps per day using an accelerometer. Researchers then examined associations between physical activity and mortality, seeking to identify daily step count cutoff points for predicting all-cause mortality.

Among the 87 patients with IPF enrolled in the study, 73 were male and 44 patient died during follow-up (median follow up was 54 months). The study results indicated that daily step count was an independent predictor of all-cause mortality (HR = 0.820) with the optimal cutoff point for 1-year mortality being 3473 steps per day. Mortality was significantly lower in patients with a daily step count exceeding 3473 steps when compared with those whose count was 3473 or less (HR = 0.395).

The study authors wrote, “Physical activity was a significant prognostic factor after adjusting for disease severity, patient attributes, physiological measures, and [6-minute walking distance].” They added, “These findings suggest that step count might be a simple and important assessment tool for clinical management in patients with IPF.”


Shingai K, Matsuda T, Kondoh Y, et al. Cutoff Points for Step Count to Predict 1-year All-Cause Mortality in Patients with Idiopathic Pulmonary Fibrosis. Respiration. 2021;100(12):1151-1157. doi:10.1159/000517030