An investigation of the reliability and utility of the Axivity AX accelerometer compared to a Actigraph GT3X+ accelerometer in healthy adults within free-living conditions (360G-Wellcome-211446_Z_18_Z)

The aim of this project is to investigate the validity of the Axivity accelerometer to measure PA in healthy adults within free-living conditions by comparing step counts to a gold standard Actigraph accelerometer. A sample group of 10 healthy participants will be recruited who will wear the monitors continuously for seven consecutive days. No change to the participant’s current level of activity will be required as this project is purely observational. After the data collection period, the monitors will be collected from the participants, and the data downloaded to a computer by the researcher. During the collection period the participants will also keep an activity log which will be collected at the end. Utility of wearing each monitor will also be recorded. Descriptive statistics will be used to summarise study populations demographic and other characteristics. To investigate validity of the Axivity monitor, the percentage agreement between Axivity and ActiGraph for step count will be calculated using limits of agreement (LOA). ActiGraph will be considered the criterion measure and a value close to or equal to 100%, with narrow LOA will indicate higher levels of agreement between the two measures under investigation.