Neighborhoods play a huge role in the development of individuals in a population. It is stated that the social, institutional, and physical built environment of neighborhoods have a direct linkage to a large quantity of poor health outcomes. These include STDs, chronic heart disease, acute disease, birth outcomes, and all cause mortality. The dynamic of neighborhood boundaries are heavily regarded and accepted in urban health research. The perceptions of these boundaries can be studied across a variety of outlooks such as social connections in public facilities such as schools and shopping malls, and in certain physical barriers such as a pathway between two individuals. Public health researchers have often leaned towards studying predetermined boundaries since they line up with various health data sources coming from the census tracts in the United States.
Census block The Inner-City Mental Health Study Predicting HIV/AIDS, Club and Other Drug Transitions (IMPACT) is stated as a 5 year program that looks to implement interventions targeted towards the increasing prevalence of urban social and physical environment that shape individual sexual and drug use risk behaviors in the New York City area. The neighborhoods in this area were identified and delineated using census block group boundaries, which help break up neighborhood socio-demographic characteristics on a smaller scale for research. The block groups although need to contain a population with an efficient density to consider