Remote Actigraphy is Seasonally Variable with Implications for Clinical Monitoring

Introduction Remote measurement of physical activity and cardiopulmonary haemodynamics is increasingly being used in clinical practice and trials.(1) Structured exercise testing is an established clinical tool and regulatory endpoint,(3) however, passively generated activity data, potentially more reflective of real-world patient behaviour, remains investigational. Seasonal variation in passively collected physical activity has been observed in the general population and patients with chronic obstructive pulmonary disease.(4) Despite this, actigraphy has been used as a primary endpoint in regulatory trials of therapies for interstitial lung disease-associated pulmonary hypertension.(2) The seasonal variation of structured exercise testing and cardiopulmonary haemodynamics remains unexplored.