RESUMEN
OBJECTIVES: Non-wear time algorithms have not been validated in pregnant women with overweight/obesity (PW-OW/OB), potentially leading to misclassification of sedentary/activity data, and inaccurate estimates of how physical activity is associated with pregnancy outcomes. We examined: (1) validity/reliability of non-wear time algorithms in PW-OW/OB by comparing wear time from five algorithms to a self-report criterion and (2) whether these algorithms over- or underestimated sedentary behaviors. DESIGN: PW-OW/OB (Nâ¯=â¯19) from the Healthy Mom Zone randomized controlled trial wore an ActiGraph GT3xâ¯+â¯for 7 consecutive days between 8-12 weeks gestation. METHODS: Non-wear algorithms (i.e., consecutive strings of zero acceleration in 60-second epochs) were tested at 60, 90, 120, 150, and 180-min. The monitor registered sedentary minutes as activity counts 0-99. Women completed daily self-report logs to report wear time. RESULTS: Intraclass correlation coefficients for each algorithm were 0.96-0.97; Bland-Altman plots revealed no bias; mean absolute percent errors were <10%. Compared to self-report (Mâ¯=â¯829.5, SDâ¯=â¯62.1), equivalency testing revealed algorithm wear times (min/day) were equivalent: 60- (Mâ¯=â¯816.4, SDâ¯=â¯58.4), 90- (Mâ¯=â¯827.5, SDâ¯=â¯61.4), 120- (Mâ¯=â¯830.8, SDâ¯=â¯65.2), 150- (Mâ¯=â¯833.8, SDâ¯=â¯64.6) and 180-min (Mâ¯=â¯837.4, SDâ¯=â¯65.4). Repeated measures ANOVA showed 60- and 90-min algorithms may underestimate sedentary minutes compared to 150- and 180-min algorithms. CONCLUSIONS: The 60, 90, 120, 150, and 180-min algorithms are valid and reliable for estimating wear time in PW-OW/OB. However, implementing algorithms with a higher threshold for consecutive zero counts (i.e., ≥150-min) can avoid the risk of misclassifying sedentary data.