Enhancing Physical Activity Assessment In A French Large Cohort: Feasibility And Acceptability Of Wearable Accelerometers

PURPOSE: The aim of this study was to assess the feasibility and acceptability of using three commercially available accelerometer devices in a subsample of the NutriNet Santé cohort. METHODS: Participants wore three accelerometers (FitBit®, ActivPal®, ActiGraph®) for seven consecutive days. Feasibility was assessed based on the accelerometer wear time data reported in a log dairy by participants. After the 7-day wear period, participants completed an online specific questionnaire with 19 items, regarding their acceptance of using each accelerometer. This questionnaire was developed based on the Technology Acceptance Model (TAM), which identifies the determinants of technology acceptance: perceived usefulness and perceived ease of use. A 5-point Likert scale was used on each item to express the level of agreement, ranging from 1 (strongly disagree) to 5 (strongly agree). RESULTS: From this ancillary study, 126 participants (62 men, 64 women), aged 46,3 ± 11,3 years were included. In terms of feasibility, all three accelerometers showed a high level of compliance with significant differences observed among them (p < 0.0001). The ActivPal® recorded the highest daily wear time (Median: 1440 minutes; 25th-95th centiles :1440 - 1440) followed by the FitBit® watch (Median: 1440 minutes; 25th-95th centiles :1421 - 1440) and the ActiGraph® (Median: 930 minutes; 25th-95th centiles :855 - 1020) (p < 0.0001). All participants validated their week of PA assessment (i.e at least 4 valid days), resulting in 1,049 valid days (person×days) for the ActivPal®, 1,046 (person×days) for the FitBit® watch, and 1,006 (person×days) for the ActiGraph®. The acceptability assessment based on the questionnaire showed that the FitBit® received the highest acceptability score (80,5 ± 8,13) and the ActiGraph® the lowest score (71,7 ± 8,68), although all three devices achieved an overall satisfactory score (p < 0.0001). CONCLUSIONS: Results from our study showed that the FitBit® watch is the most suitable device for measuring PA in free-living conditions in the NutriNet-Santé study. The large-scale use of such a device must now be evaluated in terms of logistics, cost, and data privacy.