BOX 5-1 Small-Area Analysis for Detroit and Newark Detroit, Michigan, and Newark, New Jersey, are cities with high poverty rates and large minority populations. Detroit residents in particular have problems with access to primary care. The immunization coverage rates of both cities are among the lowest for municipalities in the country and are well below the rates in the rest of their respective states. Detroit's rate for the 4:3:1 series for 2-year-olds in 1998 was 71.6 percent, while the rate for the rest of Michigan was 80.0 percent; Newark's rate in the same year was 66.3 percent, while that for the rest of New Jersey was 85.9 percent. In Detroit, a multiyear CDC grant funds the university-based Child Health Network Immunization Project (CHNIP), providing $1.5 million for each of 5 years for innovations in practices designed to improve immunization coverage and for evaluation of these practices. The Detroit Medical Center at Wayne State University initially undertook neighborhood-specific door-to-door surveys to determine local health care resources and access to primary care providers. These surveys represented an effort to identify neighborhoods in which children were most at risk for underimmunization, and thus the most appropriate targets for CHNIP's outreach and facilitation services. This neighborhood-based assessment was conducted independently of the city's health department, which has neither the technical nor financial resources needed to conduct this type of study. The Newark health department likewise has not conducted any small-area surveys of immunization coverage or access to primary care in recent years. It has, however, applied to the State of New Jersey for Public Health Priority Funds--state-appropriated monies that must be used for state-identified priorities--to conduct a study of immunization coverage rates within selected neighborhoods. City health officials and leaders appreciate the value of small-area analysis of immunization coverage rates in identifying pockets of need and targeting resources and special interventions accordingly. They frequently lack the resources needed to conduct such special studies and interventions as a routine function, however, and thus depend for this purpose on state and federal initiatives and resources.