Reliability of pedometers to measure step counts in patients with chronic respiratory disease

There are a variety of devices currently available to measure physical activity. Activity monitors are technologically advanced and provide complex data, leading to higher costs. Pedometers are simple, inexpensive devices that provide easy-to-view data. The aim of this study was to determine the reliability of pedometer step counting during slow walking speeds, typical of patients with chronic respiratory disease.

The reproducibility of 8 pedometers was initially determined at slow walking speeds in a healthy individual. Thereafter, pedometer step counting was compared with an activity monitor and visual step counts in 9 healthy subjects and 48 patients with chronic respiratory disease.

Pedometers were reproducible on the same wearer, on consecutive occasions, although they were not interchangeable. During healthy subject walking, there were no significant differences between the pedometer and activity monitor at all speeds. However, both significantly undercounted steps at slower walking speeds (P < .01). At slow and medium walking speeds with patients with chronic respiratory disease, both the pedometer and activity monitor significantly undercounted steps (P < .001 for both pedometer and activity monitor at slow and P < .003 for pedometer and P < .004 for activity monitor at medium speeds) compared with visual counts.

Pedometers are an inexpensive and simple alternative to activity monitors and appear to be reliable during faster walking in both healthy subjects and patients with chronic respiratory disease. However, caution should be applied during slow walking speeds because of undercounting steps, causing misleading data that could become demotivating when used as a training adjunct.