Monitoring mobility in older adults using a global positioning system (GPS) smartwatch and accelerometer: A validation study

Background
There is interest in identifying the most reliable method for detecting early mobility limitations. Accelerometry and Global Positioning System (GPS) could provide insight into declines in mobility, but few studies have used this multi-sensor approach to monitor mobility in older adults. 
Methods
Thirty-two volunteers (66.2±6.3 years) agreed to participate in our validation study. We conducted two experiments to determine the validity of the TicWatch S2 and Pro 3 Ultra GPS models against the Qstarz receiver in measuring life-space mobility, trip frequency, duration, and mode. We also assessed the accuracy of the TicWatch in measuring step count and agreement with the ActiGraph wGT3X-BT for activity counts and sedentary behavior. Participants wore devices simultaneously for three consecutive days and recorded activity and trip information.
Results
The TicWatch Pro 3 Ultra GPS performed better than the S2 model and was similar to the Qstarz in all tested trip-related measures, ..., We conducted two experiments to validate the TicWatch for collecting movement and navigation data: 1) we compared the TicWatch S2 against the Qstarz BT-Q1000X GPS Data Logger to measure life-space mobility, trip frequency, and duration. We also assessed the agreement of the TicWatch S2 in measuring step count against an observer, activity counts per minute (CPM), and sedentary and non-sedentary activity using ActiGraph's proprietary algorithms; 2) we compared the TicWatch Pro 3 Ultra GPS against a stand-alone Qstarz BT-Q1000X GPS Data Logger to measure life-space mobility, trip frequency and duration, and mode of transportation. We evaluated the level of agreement between the TicWatch Pro 3 Ultra GPS in measuring steps compared to direct measures of step count reported by the participants. Additionally, we tested two different GPS configurations of the TicWatch Pro 3 Ultra GPS in a free-living study setting to observe battery life performance: a) periodic fix collection every 10 seconds..., , # MONITORING MOBILITY IN OLDER ADULTS USING A GLOBAL POSITIONING SYSTEM (GPS) SMARTWATCH AND ACCELEROMETER: A VALIDATION STUDY

### Brief description of dataset contents, experimental procedures and results.

Twenty-five volunteers participated in our validation study. We conducted two experiments to validate the TicWatch S2 and Pro 3 Ultra GPS for collecting accelerometer data against the ActiGraph wBT3X and life space measure and trip frequency, duration and mode against the Qstarz BT-Q1000X GPS Data Logger. We also assessed the accuracy of the TicWatch in measuring step count and agreement with the ActiGraph wGT3X-BT for activity counts and sedentary behavior. Participants wore devices simultaneously for three consecutive days and recorded activity and trip information.
In Experiment 1, participants were provided with three devices, the TicWatch S2, Qstarz GPS Data Logger and the ActiGraph. They were instructed to wear the TicWatch S2 and the ActiGraph on the non-dominant wrist simul...