Activity monitoring in assessing activities of daily living

Individuals who have active lifestyles appear to reap substantial benefits. It is therefore of interest to assess level of activity and to determine whether interventions are capable of altering activities of daily life. Questionnaires are often employed because of their simplicity, but objective measures are sought. Long-term assessment of energy expenditure, either through doubly labeled water analysis or through measurements of expired gases are expensive and often impractical. Activity monitors include pedometers, heart rate monitors, accelerometers and integrated multisensor systems. Rapidly advancing activity monitor technology has enabled long-term use and facilitated downloading of recordings to computers where sophisticated analysis of activity patterns can be made. Accelerometer-based systems have received the most attention. When applied to chronic obstructive pulmonary disease patients, accelerometric monitors have demonstrated low levels of activity; those using long-term oxygen and those having exacerbations are particularly inactive.