Application of the Rosetta Stone to understand how much MVPA preschoolers accumulate: A systematic review.

OBJECTIVES: This study illustrates the utility of the Rosetta Stone equations for comparing estimates of preschool-age children's moderate-to-vigorous physical activity (MVPA) across studies utilizing different cutpoints.

DESIGN: Systematic review.

METHODS: A search of online databases was conducted to identify studies that reported daily minutes of MVPA in preschoolers using the cutpoints from which Rosetta Stone equations have been developed. Mean MVPA minday-1 from each study and the transformed estimate using the Rosetta Stone equations were compared across 7 sets of cutpoints. The weighted mean was used to calculate absolute differences between the MVPA estimates of studies using the same cutpoints (e.g all studies that have used Pate cutpoint), and from all of the remaining studies using different cutpoints (e.g., all remaining studies that have not used Pate cutpoint), before and after the Rosetta Stone transformation.

RESULTS: A total of 33 manuscripts met the eligibility criteria and reported MVPA for 12,178 preschoolers (50% girls). The mean MVPA for the total sample ranged from 21.1 (Puyau cutpoint) to 288.6 (Freedson cutpoints) minday-1 . The difference between studies using the same cutpoint and estimates from remaining studies using different cutpoints was 82.4 and 80.0minday-1 for boys and girls, respectively. These differences were reduced to approximately 14minday-1 for boys and girls, after Rosetta Stone transformations.

CONCLUSIONS: The Rosetta Stone equations substantially reduced the differences across studies that utilize different cutpoints and improved the ability to interpret findings across studies. Future equations should be developed for sedentary and total physical activity, as well as, comparisons across different devices and placements.