Mapping physical activity patterns in hospitalised patients with moderate to severe acquired brain injury - MAP-ABI: Protocol for an observational study.

Introduction: The physical activity level in patients hospitalised for rehabilitation across multiple diagnoses is low. Moderate to severe acquired brain injury further reduces activity levels as impaired physical and cognitive functioning affect mobility independence. Therefore, supervised out-of-bed mobilisation and physical activity training are essential rehabilitation strategies. Few studies have measured the physical activity patterns in the early phases of rehabilitation after moderate to severe brain injury. Objectives: To map and quantify physical activity patterns in patients admitted to brain injury rehabilitation. Further, to investigate which factors are associated with activity and if the early physical activity level is associated with functional outcome at discharge. Methods: This observational study includes patients admitted to rehabilitation after moderate to severe acquired brain injury. Mobility and physical activity patterns are measured continuously during rehabilitation at two separate seven-day periods using a wearable activity tracker. Activity will be categorised into four levels and presented descriptively. Linear and logistic regression models will analyse associations between descriptive variables and activity levels. Discussion: This protocol describes an observational study investigating patients' mobility and physical activity patterns with moderate to severe acquired brain injury during in-hospital rehabilitation. The ability to increase the amount of mobilisation and physical activity in subgroups may have profound consequences on the rehabilitation outcome. Furthermore, data from this study may be used to inform a large variety of trials investigating physical rehabilitation interventions. (NCT05571462).