Evaluation of Real-World Mobility Recovery after Hip Fracture using Digital Mobility Outcomes

Abstract

BackgroundThe main focus of rehabilitation following hip fracture is to regain mobility.ObjectivesTo estimate the progression of real-world mobility the first year after hip fracture using digital mobility outcomes.DesignAn exploratory, prospective cohort study with pooled data from four previously conducted clinical trials.Setting and SubjectsWe combined data from the Trondheim Hip Fracture Trial and Eva-Hip Trial in Trondheim, Norway, and the PROFinD 1 and PROFinD 2 trials in Stuttgart and Heidelberg, Germany, resulting in a sample of 717 hip fracture patients aged ≥65 years.MethodsEach of the trials assessed mobility using body-fixed sensors (activPAL™) at three time points, collectively providing observations across the entire first year post-surgery. The following 24-hour DMOs were calculated: total walking duration (minutes), maximum number of steps within a walking bout, and number of sit-to-stand-to-walk transfers. Continuous one-year progression of the median, the 25thpercentile, and the 75thpercentile were estimated using quantile regression models with splines.ResultsThe dataset contained 5,909 observation days. The median daily total walking duration increased until 36 weeks post-surgery reaching 40 minutes; daily maximum number of steps within a walking bout increased during the first eight weeks and then stabilized at less than 100 steps; daily sit-to-stand-to-walk transfers reached a plateau after six weeks with less than 40 transfers.ConclusionsThe three DMOs progressed differently and attained plateau levels at varying times during the first year after hip fracture, indicating that these Digital Mobility Outcomes provide complementary information about different aspects of mobility recovery.