Do perceptions of neighborhood safety modify the effectiveness of an intervention to promote physical activity, a major correlate of obesity?

Background: Inequitable environments contribute to excess obesity and cardiovascular disease risk that disproportionately affects residents of lower income communities. While a substantial body of research documents associations between these neighborhood environments and the health of their residents, there is relatively little evidence examining how these environments may influence the effectiveness of interventions designed to promote health. In this analysis, we examine the impact of perceptions of neighborhood safety on the effectiveness of the Walk Your Heart to Health intervention, designed to promote physical activity among predominantly Black and Latino women in low to moderate income urban neighborhoods. Evidence suggests that physical activity decreases central adiposity, or the tendency for fat to accumulate in the abdominal area, which in turn can reduce the burden of cardiovascular disease in Black and Latino women. Method: Participants were assigned randomly into intervention or lagged intervention walking groups. Walkers met three times each week at a community site. Walks were led by Community Health Workers. Participation was tracked throughout the 32 week study period, along with psychosocial, anthropometric and pedometer data. There were 698 participants of which 572 were women. Results: Preliminary results show that participation predicts physical activity (p<.001).In addition, participants who walk more steps from baseline to 8 weeks significantly reduce their waist circumference (p<.001). Perceptions of safety do not modify the association between participation and physical activity or the association between physical activity and central adiposity.