Department of Human Nutrition and Hospitality Management
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Browsing Department of Human Nutrition and Hospitality Management by Subject "Accuracy"
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Item A catalog of validity indices for step counting wearable technologies during treadmill walking: the CADENCE-adults study(BMC, 2022) Mora-Gonzalez, Jose; Gould, Zachary R.; Moore, Christopher C.; Aguiar, Elroy J.; Ducharme, Scott W.; Schuna, John M., Jr.; Barreira, Tiago, V; Staudenmayer, John; McAvoy, Cayla R.; Boikova, Mariya; Miller, Taavy A.; Tudor-Locke, Catrine; University of Granada; University of North Carolina; University of North Carolina Charlotte; University of Massachusetts Amherst; University of North Carolina Chapel Hill; University of Alabama Tuscaloosa; California State University Long Beach; Oregon State University; Syracuse UniversityBackground Standardized validation indices (i.e., accuracy, bias, and precision) provide a comprehensive comparison of step counting wearable technologies. Purpose To expand a previously published child/youth catalog of validity indices to include adults (21-40, 41-60 and 61-85 years of age) assessed across a range of treadmill speeds (slow [0.8-3.2 km/h], normal [4.0-6.4 km/h], fast [7.2-8.0 km/h]) and device wear locations (ankle, thigh, waist, and wrist). Methods Two hundred fifty-eight adults (52.5 +/- 18.7 years, 49.6% female) participated in this laboratory-based study and performed a series of 5-min treadmill bouts while wearing multiple devices; 21 devices in total were evaluated over the course of this multi-year cross-sectional study (2015-2019). The criterion measure was directly observed steps. Computed validity indices included accuracy (mean absolute percentage error, MAPE), bias (mean percentage error, MPE), and precision (correlation coefficient, r; standard deviation, SD; coefficient of variation, CoV). Results Over the range of normal speeds, 15 devices (Actical, waist-worn ActiGraph GT9X, activPAL, Apple Watch Series 1, Fitbit Ionic, Fitbit One, Fitbit Zip, Garmin vivoactive 3, Garmin vivofit 3, waist-worn GENEActiv, NL-1000, PiezoRx, Samsung Gear Fit2, Samsung Gear Fit2 Pro, and StepWatch) performed at < 5% MAPE. The wrist-worn ActiGraph GT9X displayed the worst accuracy across normal speeds (MAPE = 52%). On average, accuracy was compromised across slow walking speeds for all wearable technologies (MAPE = 40%) while all performed best across normal speeds (MAPE = 7%). When analyzing the data by wear locations, the ankle and thigh demonstrated the best accuracy (both MAPE = 1%), followed by the waist (3%) and the wrist (15%) across normal speeds. There were significant effects of speed, wear location, and age group on accuracy and bias (both p < 0.001) and precision (p <= 0.045). Conclusions Standardized validation indices cataloged by speed, wear location, and age group across the adult lifespan facilitate selecting, evaluating, or comparing performance of step counting wearable technologies. Speed, wear location, and age displayed a significant effect on accuracy, bias, and precision. Overall, reduced performance was associated with very slow walking speeds (0.8 to 3.2 km/h). Ankle- and thigh-located devices logged the highest accuracy, while those located at the wrist reported the worst accuracy.Item A catalog of validity indices for step counting wearable technologies during treadmill walking: the CADENCE-Kids study(BMC, 2021) Gould, Zachary R.; Mora-Gonzalez, Jose; Aguiar, Elroy J.; Schuna, John M., Jr.; Barreira, Tiago, V; Moore, Christopher C.; Staudenmayer, John; Tudor-Locke, Catrine; University of Massachusetts Amherst; University of North Carolina; University of North Carolina Charlotte; University of Alabama Tuscaloosa; Oregon State University; Syracuse University; University of North Carolina Chapel HillBackground: Wearable technologies play an important role in measuring physical activity (PA) and promoting health. Standardized validation indices (i.e., accuracy, bias, and precision) compare performance of step counting wearable technologies in young people. Purpose: To produce a catalog of validity indices for step counting wearable technologies assessed during different treadmill speeds (slow [0.8-3.2 km/h], normal [4.0-6.4 km/h], fast [7.2-8.0 km/h]), wear locations (waist, wrist/arm, thigh, and ankle), and age groups (children, 6-12 years; adolescents, 13-17 years; young adults, 18-20 years). Methods: One hundred seventeen individuals (13.1 +/- 4.2 years, 50.4% female) participated in this cross-sectional study and completed 5-min treadmill bouts (0.8 km/h to 8.0 km/h) while wearing eight devices (Waist Actical, ActiGraph GT3X+, NL-1000, SW-200; Wrist ActiGraph GT3X+; Arm: SenseWear; Thigh: activPAL; Ankle: StepWatch). Directly observed steps served as the criterion measure. Accuracy (mean absolute percentage error, MAPE), bias (mean percentage error, MPE), and precision (correlation coefficient, r; standard deviation, SD; coefficient of variation, CoV) were computed. Results: Five of the eight tested wearable technologies (i.e., Actical, waist-worn ActiGraph GT3X+, activPAL, StepWatch, and SW-200) performed at < 5% MAPE over the range of normal speeds. More generally, waist (MAPE = 4%), thigh (4%) and ankle (5%) locations displayed higher accuracy than the wrist location (23%) at normal speeds. On average, all wearable technologies displayed the lowest accuracy across slow speeds (MAPE = 50.1 +/- 35.5%), and the highest accuracy across normal speeds (MAPE = 15.9 +/- 21.7%). Speed and wear location had a significant effect on accuracy and bias (P < 0.001), but not on precision (P> 0.05). Age did not have any effect (P > 0.05). Conclusions: Standardized validation indices focused on accuracy, bias, and precision were cataloged by speed, wear location, and age group to serve as important reference points when selecting and/or evaluating device performance in young people moving forward. Reduced performance can be expected at very slow walking speeds (0.8 to 3.2 km/h) for all devices. Ankle-worn and thigh-worn devices demonstrated the highest accuracy. Speed and wear location had a significant effect on accuracy and bias, but not precision.