The Fitbit One Physical Activity Tracker in Men With Prostate Cancer: Validation Study

Abstract

BackgroundPhysical activity after cancer diagnosis improves quality of life and may lengthen survival. However, objective data in cancer survivors are limited and no physical activity tracker has been validated for use in this population.ObjectiveThe aim of this study was to validate the Fitbit One’s measures of physical activity over 7 days in free-living men with localized prostate cancer.MethodsWe validated the Fitbit One against the gold-standard ActiGraph GT3X+ accelerometer in 22 prostate cancer survivors under free-living conditions for 7 days. We also compared these devices with the HJ-322U Tri-axis USB Omron pedometer and a physical activity diary. We used descriptive statistics (eg, mean, standard deviation, median, interquartile range) and boxplots to examine the distribution of average daily light, moderate, and vigorous physical activity and steps measured by each device and the diary. We used Pearson and Spearman rank correlation coefficients to compare measures of physical activity and steps between the devices and the diary.ResultsOn average, the men wore the devices for 5.8 days. The mean (SD) moderate-to-vigorous physical activity (MVPA; minutes/day) measured was 100 (48) via Fitbit, 51 (29) via ActiGraph, and 110 (78) via diary. The mean (SD) steps/day was 8724 (3535) via Fitbit, 8024 (3231) via ActiGraph, and 6399 (3476) via pedometer. Activity measures were well correlated between the Fitbit and ActiGraph: 0.85 for MPVA and 0.94 for steps (all P<.001). The Fitbit’s step measurements were well correlated with the pedometer (0.67, P=.001), and the Fitbit’s measure of MVPA was well correlated with self-reported activity in the diary (0.84; P<.001).ConclusionsAmong prostate cancer survivors, the Fitbit One’s activity and step measurements were well correlated with the ActiGraph GT3X+ and Omron pedometer. However, the Fitbit One measured two times more MVPA on average compared with the ActiGraph.

Harnessing consumer smartphone and wearable sensors for clinical cancer research

“…Collection of activity data using consumer devices has been demonstrated to be feasible and acceptable among cancer patients in active treatment 17 – 20 . The wearable device literature builds on early studies with older-generation research-grade accelerometers 21 , which have been shown to correlate with consumer activity tracker data in cancer patients 22 . Unlike research-grade actigraphy devices, which are costly, require specialized software to access and analyze the data, and are commonly worn for a week or less, consumer wearable devices are affordable and designed to be comfortable and convenient to wear continuously with easily recharged batteries that enable long-term data collection.…”

Counting Steps in Activities of Daily Living in People With a Chronic Disease Using Nine Commercially Available Fitness Trackers: Cross-Sectional Validity Study

“…Of the 12 identified studies, only 3 evaluated activities of daily living (free living or an activity protocol) in people with a chronic disease [ 22 - 24 ]; however, these studies only tested noncommercially available activity trackers and mainly evaluated energy expenditure instead of step count. Results from other studies with participants with chronic diseases are not generalizable to daily practice because they did not have step count as the primary outcome (eg, mostly energy expenditure) [ 25 - 31 ], involved only walking and no other activities of daily living [ 32 - 35 ], or free living conditions were not protocoled (eg, cardiac patients [ 36 ] and patients with COPD [ 37 ] or cancer [ 38 ]).…”

Application of Activity Trackers among Nursing Home Residents—A Pilot and Feasibility Study on Physical Activity Behavior, Usage Behavior, Acceptance, Usability and Motivational Impact

“…Furthermore, several studies have proven that the validity of activity trackers is generally lower at low gait speed [ 21 , 77 , 78 ]. Nevertheless, devices of the Fitbit brand have been validated for use in community-dwelling older adults [ 45 , 46 , 47 ], rehabilitation, and cancer patients [ 48 , 49 ]. Given the increasing use of activity trackers to assess PA and sedentary behavior in all age and social groups, there is a high need for further validations.…”

“…The long battery lifetime of up to 6 months makes it suitable for use in long-term studies. Recently among others, Fitbit devices have been validated for use in community-dwelling older adults [ 45 , 46 , 47 ], rehabilitation, and cancer patients [ 48 , 49 ]. Step counts are the primary measure of activity trackers.…”