A calibration protocol for population-specific accelerometer cut-points in children
Data(s) |
10/05/2012
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Resumo |
<b>Purpose</b><br /><br />To test a field-based protocol using intermittent activities representative of children's physical activity behaviours, to generate behaviourally valid, population-specific accelerometer cut-points for sedentary behaviour, moderate, and vigorous physical activity.<br /><b>Methods</b><br /><br />Twenty-eight children (46% boys) aged 10–11 years wore a hip-mounted uniaxial GT1M ActiGraph and engaged in 6 activities representative of children's play. A validated direct observation protocol was used as the criterion measure of physical activity. Receiver Operating Characteristics (ROC) curve analyses were conducted with four semi-structured activities to determine the accelerometer cut-points. To examine classification differences, cut-points were cross-validated with free-play and DVD viewing activities.<br /><b>Results</b><br /><br />Cut-points of ≤372, >2160 and >4806 counts•min−1 representing sedentary, moderate and vigorous intensity thresholds, respectively, provided the optimal balance between the related needs for sensitivity (accurately detecting activity) and specificity (limiting misclassification of the activity). Cross-validation data demonstrated that these values yielded the best overall kappa scores (0.97; 0.71; 0.62), and a high classification agreement (98.6%; 89.0%; 87.2%), respectively. Specificity values of 96–97% showed that the developed cut-points accurately detected physical activity, and sensitivity values (89–99%) indicated that minutes of activity were seldom incorrectly classified as inactivity.<br /><b>Conclusion</b><br /><br />The development of an inexpensive and replicable field-based protocol to generate behaviourally valid and population-specific accelerometer cut-points may improve the classification of physical activity levels in children, which could enhance subsequent intervention and observational studies.<br /> |
Identificador | |
Idioma(s) |
eng |
Publicador |
Public Library of Science |
Relação |
http://dro.deakin.edu.au/eserv/DU:30046180/ridgers-acalibration-2012.pdf |
Direitos |
2012, Mackintosh et al. |
Palavras-Chave | #children #physical activity #behaviour |
Tipo |
Journal Article |