Total Hip Replacement Recipients: Location Matters When Measuring Activity

Total hip replacement (THR) is a commonly used and effective treatment for patients with end-stage osteoarthritis. However, driving and activity has not been investigated among THR recipients. Furthermore, there is a lack of consensus when measuring activity pre to post-THR. Additionally, there is a dearth of studies that examine differences in activity between younger and older THR recipients. Three studies were completed to form this thesis. Study 1 identified and corrected for false positive activity while driving as part of a methodological approach to combining accelerometer-based activity data and GPS-based location data. Studies 2 and 3 employed the methods from Study 1 to measure differences in activity before and after THR and between younger and older groups of THR recipients. The results from Study 1 showed that the reporting of activity in patients undergoing THR should be stratified by location so false positive activity can be identified and corrected for while driving. The results of Study 2 supported the reporting of activity stratified by location and showed an improvement in activity in the not-home stratum. Results from Study 3 showed that younger THR recipients are more active than older THR recipients across different location strata and further supported the stratification of activity by location in the THR population and different age groups. Overall, this thesis demonstrated that when measuring activity in patients undergoing THR, location should be considered. This thesis found that false positive activity can occur when non-patient generated activity is not corrected for, which can amount to approximately a 4.9% overestimation of activity counts. From before to after surgery, while change in activity was not observed in the home stratum, it was observed in the not-home stratum. Similarly, differences between young and old groups of THR recipients revealed differences between the groups in both locations (home, not home).