Comparison of Two Objective Monitors for Assessing Physical Activity and Sedentary Behaviors in Bariatric Surgery Patients

Background Objective quantification of physical activity (PA) is needed to understand PA and sedentary behaviors in bariatric surgery patients, yet it is unclear whether PA estimates produced by different monitors are comparable and can be interpreted similarly across studies. Methods We compared PA estimates from the Stayhealthy RT3 triaxial accelerometer (RT3) and the Sensewear Pro 2 Armband (SWA) at both the group and individual participant level. Bariatric surgery candidates were instructed to wear the RT3 and SWA during waking hours for 7 days. Participants meeting valid wear time requirements (≥4 days of ≥8 h/day) for both monitors were included in the analyses. Time spent in sedentary ( 0.05). While the average difference in TPA between the two monitors at the group level was 7.2 ± 64.2 min; the average difference between the two monitors for each participant was 45.6 ± 45.4 min. At the group level, the RT3 and SWA provide similar estimates of PA and sedentary behaviors; however, concordance between monitors may be compromised at the individual level. Conclusions Findings related to PA and sedentary behaviors at the group level can be interpreted similarly across studies when either monitor is used.