Objective Measurement of Physical Activity in Preschool Children: A Review of Validation Studies and Establishment of Cut-Points

Abstract
Objective: The purpose of this literature review is to examine the most psychometrically sound (e.g., valid and reliable) instruments measuring physical activity (PA) so that reflection of preschool children’s activity and documentation of intervention effects on preschool child PA is accurate.
Methods: Rigorous validation and calibration studies and those studies designed to test the psychometric properties of PA measurement instruments were specifically sought out to include in this review. Articles were excluded if they did not include specific information about the validity and reliability of the PA measures used with preschool children.
Discussion: Of the six articles reviewed, the systematic review used the most rigorous protocols to conduct its review, yielding the highest level of evidence appraising several validation studies. Because Pfeiffer et al. (2006) utilized the most valid and reliable criterion measure (Cosmed® portable metabolic system), the validation study this research team conducted is deemed to have identified the most valid and reliable cut points to utilize when reducing accelerometry data.
Conclusion: Current cut-points vary widely and greatly affect the reported results of a study. Therefore, it is critical that authors reference validation studies used to support the cut-points that were employed in the data-reduction phase. Currently, validation methods have been identified using high quality criterion measures in rigorous validation studies and thus it is strongly recommended that those cut points be used in data reduction processes.