Preliminary evaluation of reliability and criterion validity of Actiwatch-Score

The restoration of normal physical activity is a primary objective of most chronic pain rehabilitative interventions, yet few clinically practical objective measures of activation exist. Actigraphy is one technology that promises to fill this void in the field of pain outcomes assessment. This study evaluates the measurement properties of one of several commercially available actigraphs: the Actiwatch-Score (AW-S). We conducted separate trials to examine concordance between units when worn concurrently at the same and different body sites and to compare the AW-S to a validated optical three-dimensional motion-tracking system. The data indicate that the AW-S has excellent interunit reliability and good criterion validity, but its intersite reliability varies with activity type. These results suggest that this device, and those like it, warrants further investigation and is likely to yield valuable data regarding the optimal application of this technology.