Measuring and Mapping Physical Activity Disparity (PAD) Index Based on Physical Activity Environment for Children

Physical activity (PA) plays a vital role in children's physical and mental health. The built, natural, and socio-demographic environmental variables affect children's PA behaviors in various ways. However, few studies focus on systematically measuring the environmental spatiality to enhance PA research. We propose a Physical activity Access Disparity (PAD) index for children. This study aims to design, test, and apply an integrated approach to the children's PAD index. We adopt five dimensions of "access" to healthcare to measure the children's PAD index for the United States (US) and the state of Georgia at the county level. The PAD index sorts 18 environmental measures with 23 variables into accessibility, availability, accommodation, affordability, and acceptability (5 As) for children's PA. We use the self-organizing map (SOM) method to measure how the 5 As affect the PAD index values. According to the result, the children's PAD index's ranking normalizes from 0 to 1 and identifies "play oases" to "play deserts" in the US and Georgia using diverse 5 As combinations. The children's PAD index shows Low disparity in the north and coastal region and High disparity in Deep South states in the US. Moreover, the PAD index shows Low disparity and High disparity in the north and south of Georgia. The PAD index provides a valuable tool for researchers and policymakers to analyze disparity in children's "access" to the PA environment. The flexible parameters and the weighing scheme also extend the method's generality and allow users to customize the PAD index based on local preferences and conditions.