DOI: 10.7272/q6ng4nwt
title: Five year pediatric use of a digital wearable fitness device: lessons from a pilot case study

description: Objectives: Wearable fitness devices are increasingly used by the general
 population, with new applications being proposed and designed for healthy
 adults as well as adults with chronic diseases. Fewer, if any, studies of
 these devices have been conducted in healthy adolescents and teenagers,
 especially over a long period of time. The goal of this work was to
 document the successes and challenges involved in 5 years of a wearable
 fitness device use in a pediatric case study. Materials and Methods:
 Comparison of five years of step counts and minutes asleep from a teenaged
 girl and her father. Results: At 60 months, this may be the longest
 reported pediatric study involving a wearable fitness device, and the
 first simultaneously involving a parent and a child. We find step counts
 to be significantly higher for both the adult and teen on school/work
 days, along with less sleep. The teen walked significantly less towards
 the end of the 5 year study. Surprisingly, many of the adult’s and teen’s
 sleeping and step counts were correlated, possibly due to coordinated
 behaviors. Discussion: We end with several recommendations for
 pediatricians and device manufacturers, including the need for constant
 adjustments of stride length and calorie counts as teens are growing.
 Conclusion: With periodic adjustments for growth, this pilot study shows
 these devices can be used for more accurate and consistent measurements in
 adolescents and teenagers over longer periods of time, to potentially
 promote healthy behaviors.
description: Ethics: Two authors (including the lead author) collected their
 own data as citizen-scientist subjects, with their own devices that they
 obtained, initiated the analyses, then approached the Stanford
 investigators to enhance the analyses, and both of these subjects
 contributed to writing this manuscript.  The two data contributors joined
 Stanford University research protocol 56378 approved by the Stanford
 University Institutional Review Board, specifically allowing participants
 at or over age 13 years to share their past and current Fitbit measurement
 data with Stanford investigators for research purposes, with informed
 consent. Two Fitbit One devices were purchased
 (Amazon.com) on January 1, 2013 and activated shortly thereafter. The
 Fitbit One was designed to track steps walked along with pace, stairs
 climbed, sleep duration and activity.  Two participants (and co-authors
 here) simultaneously started to use the devices to track these
 measurements.  The female participant started use at age 10 years and 4
 months, and continued through her teenage years.  The adult male
 participant (father of the younger individual) started use at age 43 years
 and 9 months.  Neither had any significant prior medical history at the
 initiation of use.  Both intended the use of these devices for improving
 and maintaining general health and wellness.  The adult also intended to
 use the device to increase his walking and help in weight loss.  While
 these devices (or their subsequent versions) have still been in use since
 January 1, 2013, this analysis only covers the 60 months of use after a
 pattern of regular consistent use was seen, starting on June 1, 2013.  In
 June 2018, both participants elected to study their data together for
 research. Fitbit enables the downloading of raw level
 device data, by registering through their Application Programming
 Interface (API).  Using the API ID number that Fitbit provided, a short
 program was written in R to access the Fitbit data, serially downloading
 blocks of daily step and sleep data representing every 100 days, to cover
 the entire 60 months.  No outlier measurements were
 removed.  Sleep amounts in minutes are assigned to the wake up day. 
 Weekend nights were defined as those leading into a Saturday or Sunday,
 which are days with no school.  School days were defined as weekdays that
 were not within a set of five long holiday breaks: one week mid-winter
 break in February, one week spring break in March or April, ten week
 summer break in June-August, Thanksgiving one week break in November, and
 two week winter break between December and January.