Comparison of Omron and ActiGraph monitors in estimating daily step counts and time spent in moderate to vigorous physical activity in free-living adults

Abstract

Objective This study compared the Omron Active style Pro HJA-750C (OM) and the ActiGraph wGT3X-BT (AG) in estimating daily physical activity—step counts and time spent in moderate to vigorous physical activity (MVPA)—in free-living adults.Methods Japanese adults without gait abnormalities wore both devices during waking hours for seven consecutive days. Data were aggregated into daily steps and MVPA. A valid day required ≥10 hours of AG wear time with ≥100 and <50 000 accumulated steps from both devices. Agreement was assessed using Bland-Altman plots with multilevel analysis.Results The final dataset included 129 participants (age 23–89 years, 50.4% women), totalling 887 observations (5–7 daily observations/participant). OM estimated an overall mean of 7456 (SE 253) steps/day and 68.9 (SE 2.8) min/day in MVPA. Bland-Altman plots showed that OM estimated −56 steps/day (95% limits of agreement (LoA) = −1599; 1486) and +23 min/day (LoA = −17; 63) in MVPA compared with AG. Differences tended to increase with higher mean estimates for both step counts and MVPA.Conclusion OM estimated substantially more daily time spent in MVPA but showed similar daily step counts compared with AG. Differences were larger with higher activity levels.