Assessing Physical Activity and Sleep in Axial Spondyloarthritis: Measuring the Gap

Patients with axial spondyloarthritis (axSpA) frequently report pain, stiffness, fatigue, and sleep problems, which may lead to impaired physical activity. The majority of reported-on measures evaluating physical activity and sleep disturbance in axSpA are self-reported questionnaires, which can be impacted by patient recall (reporting bias). One objective measure, polysomnography, has been employed to evaluate sleep in patients with axSpA; however, it is an intrusive measure and cannot be used over the long term. More convenient objective measures are therefore needed to allow for the long-term assessment of both sleep and physical activity in patients’ daily lives. Wearable technology that utilizes actigraphy is increasingly being used for the objective measurement of physical activity and sleep in various therapy areas, as it is unintrusive and suitable for continuous tracking to allow longitudinal assessment. Actigraphy characterizes sleep disruption as restless movement while sleeping, which is particularly useful when studying conditions such as axSpA in which chronic pain and discomfort due to stiffness may be evident. Studies have also shown that actigraphy can effectively assess the impact of disease on physical activity. More research is needed to establish the usefulness of objective monitoring of sleep and physical activity specifically in axSpA patients over time. This review summarizes the current perspectives on physical activity and sleep quality in patients with axSpA, and the possible role of actigraphy in the future to more accurately evaluate the impact of treatment interventions on sleep and physical activity in axSpA.