摘要：Objectives. We evaluated the effect of providing a safe play space on the physical activity level of inner-city schoolchildren. Methods. In 1 of 2 matched neighborhoods, we opened a schoolyard and provided attendants to ensure children’s safety. Over the next 2 years we directly observed the number of children and their physical activity levels in the school-yard, as well as in the surrounding intervention and comparison neighborhoods. We also surveyed children in the schools in the intervention and comparison neighborhoods regarding sedentary activities. Results. After the schoolyard was opened, a mean of 71.4 children used it on weekdays and 25.8 used it on weekends during the school year. When observed, 66% of these children were physically active. The number of children who were outdoors and physically active was 84% higher in the intervention neighborhood than the comparison neighborhood. Survey results showed that children in the intervention school reported declines relative to the children in the comparison school in watching television, watching movies and DVDs, and playing video games on weekdays. Conclusion. When children were provided with a safe play space, we observed a relative increase in their physical activity. Provision of safe play spaces holds promise as a simple replicable intervention. The prevalence of overweight is rising rapidly in children. 1 Among African Americans the problem is severe: 21.8% of African American children aged 12 to 19 years are overweight. 1 The relation between inadequate physical activity and weight gain is strong and consistent. 2 , 3 In spite of national recommendations for greater physical activity, American children engage in low levels of physical activity. 4 , 5 There is increasing evidence that features of physical and social environments influence levels of physical activity. 6 – 9 A sense of safety in the neighborhood appears to be one important environmental determinant. Adults who perceive their neighborhoods to be unsafe are substantially more likely to be physically inactive than are adults who perceive their neighborhoods as safe. 10 Outdoor safety is especially important for children, because time spent outdoors is strongly associated with physical activity. 11 , 12 Parents rank safety as the most important factor in deciding whether to let their young children play in a given location. 13 A recent study found that children whose parents perceived their neighborhoods to be particularly unsafe were more than 4 times as likely to be obese than children whose parents perceived their neighborhoods to be safe. 14 Changes in family structure and work have accentuated the effect of neighborhood safety on physical activity. The proportion of children whose mothers are employed outside the home has increased in recent decades. Although preschool children whose mothers work often attend structured day-care programs or are cared for by relatives, 23% of school-aged children whose mothers are employed outside the home are left alone during afterschool hours. 15 One multisite study found that when children are in self-care, their most frequent activity by far is watching television, 16 a sedentary activity that is strongly associated with obesity. 17 The Institute of Medicine recognizes that children need more opportunities for physical activity and has recommended that schools be used as community centers for physical activity during afterschool hours. 18 In spite of the recognition of environmental effects, few interventions have been developed that increased physical activity or reduced obesity in children by changing their environment. We implemented a pilot intervention in which we provided a safe play space in a low-income, inner-city neighborhood and evaluated its effect on the physical activity of local children.
