Development and Evaluation of New Accelerometer Cut Points for Adolescent Girls

Simple item page
dc.contributor.advisorYoung, Deborah Ren_US
dc.contributor.authorKuo, JoAnnen_US
dc.contributor.departmentKinesiologyen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.date.accessioned2009-11-06T06:30:42Z
dc.date.available2009-11-06T06:30:42Z
dc.date.issued2009en_US
dc.description.abstractCurrent negative trends in adolescent disease risk factors (e.g., overweight) may be related to physical activity. To study these relationships using accelerometers, how to estimate physical activity from accelerometer counts must be better understood. PURPOSES: (1) To develop new accelerometer cut points for estimating physical activity using disease risk factors as criteria. (2) To evaluate how estimates of physical activity using these newly developed cut points agree with comparison measures (i.e., a previously suggested cut point and self-report physical activity recall questionnaires). METHODS: National Health and Nutrition Examination Survey (NHANES) and Trial of Activity for Adolescent Girls (TAAG) data were examined. New cut points were developed using iterative correlations and signal detection and receiver operating characteristic (ROC) curves. To identify new cut points, potential cut points were identified in a development sample and validated in an evaluation sample. Agreement between new cut points and comparison measures was examined using concordance correlation coefficients, Bland-Altman plots, McNemar's tests, and proportions of agreement. RESULTS: Using the correlation method, two new combinations of light, moderate, and vigorous intensity cut points were identified in NHANES (1900, 4300, and 10000 counts/min and 1900, 4000, and 5000 counts/min) and two in TAAG (1450, 1950, and 2450 counts/30 sec and 1050, 1550, and 2050 counts/30 sec). Using the signal detection/ROC curve method, eleven new cut points were identified in NHANES (ranging from 100 to 2300 counts/min) and three in TAAG (ranging from 100 to 200 counts/min). Concordance correlation coefficients for minutes of activity with a previously suggested cut point tended to be stronger (≥ 0.60) with higher cut points (≥ 2300 count/min), while those with questionnaires were less than 0.10 or the 95% confidence intervals included zero. One new cut point (1800 counts/min) was similar (p = 0.6) to a comparison measure for classifying meeting recommendations. CONCLUSIONS: Some cut points may be more strongly associated with disease risk factors than previously suggested cut points developed using oxygen consumption, but associations are not strong. The new cut points and comparison measures may be measuring different aspects of physical activity, as they were in poor agreement.en_US
dc.identifier.urihttp://hdl.handle.net/1903/9704
dc.subject.pqcontrolledHealth Sciences, Epidemiologyen_US
dc.subject.pquncontrolledaccelerometryen_US
dc.subject.pquncontrolledcardiovascular disease risk factorsen_US
dc.subject.pquncontrolledmetabolic disease risk factorsen_US
dc.subject.pquncontrolledphysical activity assessmenten_US
dc.subject.pquncontrolledphysical activity measurementen_US
dc.subject.pquncontrolledyouthen_US
dc.titleDevelopment and Evaluation of New Accelerometer Cut Points for Adolescent Girlsen_US
dc.typeDissertationen_US

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
Kuo_umd_0117E_10655.pdf
Size:
1.92 MB
Format:
Adobe Portable Document Format
Download

Collections

UMD Theses and Dissertations
Kinesiology Theses and Dissertations