National Health and Nutrition Examination Survey
Waves 2011-2012 and 2013-2014
Physical Activity Data (under Examination Data)
Actigraph GT3X+, nondominant wrist
https://wwwn.cdc.gov/nchs/data/nhanes/public/2011/manuals/2012-Physicial-Activity-Monitor-Procedures-Manual-508.pdf
Data Released in 2020 (and updated in 2022) summarized at Day/HourMinute
Monitor-independent movement summary for accelerometer data (John et al. 2019)
New measure!
We had a lot of research on activity counts - Intuition/cutoffs
Created mapping (Karas et al. 2022)
Almost 5 years to today!
BIRS conference: Use of Wearable and Implantable Devices in Health Research
Schedule: https://workshops.birs.ca/events/20w5109/schedule
Recorded Videos: https://www.birs.ca/events/2020/5-day-workshops/20w5109/videos
Identify individuals from wrist acceleromtery during walking (“fingerprinting”) (Lily Koffman et al. 2023), want to scale to large, population-based study
Raw data Available
John Staudenmayer from BIRS 2020:
From https://www.birs.ca/events/2020/5-day-workshops/20w5109/videos/watch/202002271147-Staudenmayer.html
But what if we didn’t need to “train” exactly…
stepcount
(May 25, 2021 initial commit): Scott R. Small et al. (2024)
Lily Koffman and Muschelli (2024) estimates steps using 3 gold standard data sets: OxWalk (S. R. Small et al. 2022), MAREA (Khandelwal and Wickström 2017), and Clemson (Mattfeld, Jesch, and Hoover 2017)
Lily Koffman and Muschelli (2024) estimates steps from 5 methods on this data:
stepcount
(SSL version) good for most data/metrics:stepcount
(SSL version) good for most data/metrics:L. Koffman, Crainiceanu, and Muschelli (2024) applies those methods to NHANES.
Wildly different estimates!
Mostly similar patterns by age
Fairly high correlation between methods
And more predictive of 5-year mortality (even than AC/MIMS)
Dose response relationship between steps and mortality
Takehome
Steps from different algorithms in NHANES correlated and highly predictive of mortality, but very different in absolute value
Steps more interpretable for general public than AC or MIMS, but only if we can better define or harmonize what is a “step”
Still need more large, open training data!
Still need mapping between stepcount
steps, Apple/Fitbit steps, “true” steps
The data is available (more derivatives to come):
https://physionet.org/content/minute-level-step-count-nhanes/1.0.0/
https://physionet.org/static/published-projects/minute-level-step-count-nhanes/1.0.0/
Minute level step counts from 5 algorithms:
Actilife (from Actigraph) (ActiGraph 2015)
ADEPT (Karas et al. 2021)
Verisense (x2) (Rowlands et al. 2022), (Patterson 2020)
stepcount (SSL, RF) (Scott R. Small et al. 2024)
Also:
MIMS
AC
log10 MIMS
log10 AC
Wear prediction (sleep, wake, nonwear) (Thapa-Chhetry et al. 2022)
Qualify flag (Y/N)
Ripe for functional data analysis, steps, and physical activity research!