The Neighborhood Quality of Life Study (NQLS), conducted between 2001-2005, was designed to identify environmental correlates of physical activity. This observational study of 2,200 adults aged 20-65 randomly selected from 32 neighborhoods in two regions of the U.S. developed new paradigms and measures for studying built environment associations with health behaviors.
Sallis, J.F., Saelens, B.E., Frank, L.D., Conway, T.L., Slymen, D.J., Cain, K.L., Chapman, J.E., and Kerr, J. (2009). Neighborhood built environment and income: Examining multiple health outcomes. Social Science and Medicine, 68, 1285-1293. doi:10.1016/j.socscimed.2009.01.017
Frank, L.D., Sallis, J.F., Saelens, B.E., Leary, L., Cain, K., Conway, T.L., and Hess, P.M. (2010). The development of a walkability index: Application to the Neighborhood Quality of Life Study. British Journal of Sports Medicine, 43, 124-131. Link