Evaluation of a Natural Experiment: Does the Built Environment Affect Children's Physical Activity?

Research suggests a significant positive association between youths’ physical activity (PA) and the built environment. However, not all neighborhoods provide the same opportunities to engage in PA. The purpose of this study is to evaluate if significant changes made to the built environment (i.e. development of a mixed-use center, park improvements, and streetscape enhancements) impact children’s overall PA levels. Methods. The study employed a pre-post quasi-experimental evaluation design making use of a “natural experiment” in a low-income, minority neighborhood in the city of St. Louis. Families with children(5-14yrs) were recruited from the experimental neighborhood and a comparison neighborhood of similar size and racial and economic composition. A cross-section sample of families (n=277) completed a survey assessing parental perceptions of child PA behaviors and demographic variables before and after significant built environmental improvements in the experimental neighborhood. To objectively assess PA, a subsample of children (n=32) wore accelerometers for one week at baseline and follow-up. Results. Neighborhoods were comparable at baseline in demographic composition and children’s PA levels.  Parents reported no significant change in children’s PA levels from baseline to follow up in either neighborhood. Similarly, accelerometer data showed no significant change in children’s moderate-to-vigorous PA levels in either neighborhood. While non-significant, mean PA decreased in both the experimental (39.1 to 32.8 min) and comparison (49.4 to 40.6 min) neighborhoods. Conclusions.  Enhancements to the built environment are recommended; however, results suggest additional efforts beyond built environment improvements may be needed to increase children’s activity levels, especially among low income, minority populations.