A catalog of rules, variables, and definitions applied to accelerometer data in the National Health and Nutrition Examination Survey, 2003-2006.
BACKGROUND
The National Health and Nutrition Examination Survey (NHANES) included accelerometry in the 2003-2006 data collection cycles. Researchers have used these data since their release in 2007, but the data have not been consistently treated, examined, or reported. The objective of this study was to aggregate data from studies using NHANES accelerometry data and to catalogue study decision rules, derived variables, and cut point definitions to facilitate a more uniform approach to these data.


METHODS
We conducted a PubMed search of English-language articles published (or indicated as forthcoming) from January 2007 through December 2011. Our initial search yielded 74 articles, plus 1 article that was not indexed in PubMed. After excluding 21 articles, we extracted and tabulated details on 54 studies to permit comparison among studies.


RESULTS
The 54 articles represented various descriptive, methodological, and inferential analyses. Although some decision rules for treating data (eg, criteria for minimal wear-time) were consistently applied, cut point definitions used for accelerometer-derived variables (eg, time spent in various intensities of physical activity) were especially diverse.


CONCLUSIONS
Unique research questions may require equally unique analytical approaches; some inconsistency in approaches must be tolerated if scientific discovery is to be encouraged. This catalog provides a starting point for researchers to consider relevant and/or comparable accelerometer decision rules, derived variables, and cut point definitions for their own research questions.
Walking Behavior Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA. Tudor-Locke@pbrc.edu
Catrine
C
Tudor-Locke
Sarah M
SM
Camhi
Richard P
RP
Troiano
D000054:Acceleration; D000465:Algorithms; D002377:Catalogs as Topic; D016206:Databases, Bibliographic; D017408:Guidelines as Topic; D006306:Health Surveys; D006801:Humans; D054547:National Cancer Institute (U.S.); D009749:Nutrition Surveys; D010808:Physical Examination; D039781:PubMed; D009626:Terminology as Topic; D013996:Time and Motion Studies; D014481:United States