Measuring Physical Activity Levels in Fibrotic Interstitial Lung Disease
The minimal important difference for moderate to vigorous physical activity in patients with fibrotic ILD was estimated to be 8 to 26 minutes per week.
The International Physical Activity Questionnaire long form (IPAQ-LF) was validated for measuring physical activity levels in patients with fibrotic interstitial lung disease (ILD), according to a study published in the Annals of the American Thoracic Society.
Accelerometers worn on both the waist and wrist for 7 days and postaccelerometer self-report questionnaires from outpatients with fibrotic ILD at baseline and the 6-month follow-up were recorded. Results were then used to validate the IPAQ-LF and determine minimal important differences for moderate to vigorous physical activity in this patient population.
Of the 111 study participants, the waist and wrist monitors were worn for an average of approximately 15±1 hours per day. Waist-worn activity monitors more accurately matched IPAQ-LF questionnaire results compared with wrist-worn activity monitors. The minimal important difference for moderate to vigorous physical activity in patients with fibrotic ILD was estimated to be 8 to 26 minutes per week by the waist-worn activity monitor and 13 to 58 minutes per week by IPAQ-LF.
The researchers wrote, "[W]e show that the IPAQ-LF has acceptable validity and internal consistency for the assessment of daily physical activity in patients with fibrotic ILD, and is responsive to increases in activity level of these patients."
"Our findings have important implications for patients, clinicians, and clinical researchers, providing tangible physical activity goals for patients and informing the design of clinical trials,” they concluded.
Hur S, Guler S, Khalil N, et al. Minimal important difference for physical activity and validity of the International Physical Activity Questionnaire in ILD [published September 13, 2018]. Ann Am Thorac Soc. doi:10.1513/AnnalsATS.201804-265OC