Predicting daily physical activity in patients with chronic obstructive pulmonary disease.

BackgroundObjectively measuring daily physical activity (PA) using an accelerometer is a relatively expensive and time-consuming undertaking. In routine clinical practice it would be useful to estimate PA in patients with chronic obstructive pulmonary disease (COPD) with more simple methods.ObjectivesTo evaluate whether PA can be estimated by simple tests commonly used in clinical practice in patients with COPD.MethodsThe average number of steps per day was measured for 7 days with a SenseWear Pro™ accelerometer and used as gold standard for PA. A physical activity level (PAL) of ResultsIn 70 patients with COPD (21 females) with a mean [SD] FEV(1) of 43.0 [22.0] %predicted, PA was found to be significantly and independently associated with the 6MWD (r = 0.69, 95% CI 0.54 to 0.80, pConclusionsIn patients with COPD simple tests such as the 6-Minute Walk Test, the Sit-to-Stand Test and the Zutphen Physical Activity Questionnaire cannot be used to reliably predict physical inactivity.