Documentation
Description:
Data from a subsample of 103,687 participants who wore an Axivity AX3 triaxial accelerometer on their dominant wrist were collected over a 7-day period in 2013 to 2015. It has been found that wrist-worn accelerometers can explain about 44% to 47% of the variation in PA energy expenditure as measured by doubly labelled water. For analysis, it is recommended to only include participants whose accelerometer data could be successfully calibrated, meaning that different devices provide comparable data outputs. It is also recommended to exclude participants with >1% clipped values, which occur when the sensor’s dynamic range of ±8 g is exceeded before or after calibration. In addition, it is recommended to exclude participants with implausibly high activity values, defined as average vector magnitude scores of >100 mg. Participants with insufficient wear-time should be excluded, defined as the unavailability of at least 72 hours of data or who lacked data for every 1-hour period of the 24-hour cycle (scattered over multiple days). This normally results in ~96,600 participants with accelerometer data for epidemiological analysis (see https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1003487) .
Researchers typically extract total volume of physical activity, measured as the average vector magnitude in milli-gravity (mg) units. The metric, average vector magnitude, has demonstrated good face validity in the UK Biobank (activity: 7.5% lower per decade of age) and has been validated against doubly labelled water which is a gold-standard measure for energy expenditure.
Researchers have also developed reproducible machine learning methods to infer time spent asleep, in sedentary behaviour, in light intensity activity, and in moderate intensity activity (see https://www.medrxiv.org/content/10.1101/2020.11.10.20227769v3 )
Coverage
Spatial:
Great Britain
Typical Age Range:
45-80
Follow Up:
1 - 10 YEARS
Physical Sample Availability:
NOT AVAILABLE
Pathway:
Not specified
Provenance
Origin
Purposes:
STUDY
Sources:
OTHER
Collection Situations:
COMMUNITY
Temporal
Accrual Periodicity:
STATIC
Start Date:
01 June 2013
End Date:
31 December 2019
Time Lag:
NOT APPLICABLE
Accessibility
Access
Access Request Cost:
Delivery Lead Time:
1-2 MONTHS
Jurisdictions:
GB-GBN
Data Controller:
UK Biobank
Data Processor:
UK Biobank
Usage
Data Use Limitations:
RESEARCH USE ONLY
Data Use Requirements:
RETURN TO DATABASE OR RESOURCE
Resource Creators:
UK Biobank
Format and Standards
Vocabulary Encoding Schemes:
OTHER
Conforms To:
OTHER
Languages:
en
Formats:
Time series CWA format
Enrichment and Linkage
Observations
Statistical Population
Population Description
Population Size
Measured Property
Observation Date
Persons
UK Biobank participants (men and women aged 45-80) who agreed to wear a physical activity monitor
103712
Count
31 December 2015
Origin
Name:
SDE Home