ealth-related data are used at many geographic and political levels by individuals and groups for a multitude of purposes. The focus of this paper is on what and how data are used at the local level, for what purposes and by whom, as well as some of the unique challenges and methodological manipulations involved. Examples of common and unique uses of data and the analytic challenges involved are included. Health-related data are typically used at the local level to describe populations in terms of demographics, economics, social and environmental conditions, disease prevalence, births, causes of deaths, health behaviors, and available health care resources. They may also be used to characterize access to health services and the use and cost of such services. The data are generally secondary, ie, obtained from another agency that specified form and content without local user input. The data may come from the US Census (eg, income, housing, education), the state and federal vital statistics system (eg, births, deaths, communicable disease incidence), disease registries (eg, cancer incidence, prevalence), or national or state surveys (eg, Behavioral Risk Factor Surveillance System). Other sourcesmaybeagenciesresponsibleforMedicaid,Medicare, licensing and regulation, environmental protection, education, commerce, agriculture, transportation, highway safety, or law enforcement. With increasing technology and governmental investments in data collection, there is a wealth of data available, but they may not be readily useful to or easily analyzed by the local user. Local Users and Uses The users of health-related data at the community level in North Carolina might be local chapters of voluntary health organizations (eg, American Heart Association, American Lung Association), Healthy Carolinians groups, hospitals, health departments, health care providers, professional associations, academic institutions, news media, governmental agencies, elected officials, and individual citizens interested in their own health or the health of their family and community. Typical purposes for data use include community diagnosis, program planning, policymaking, advocacy, justification of requests for resources, and program evaluation. The purposes may be categorized within the 3 core functions of public health (ie, assessment, policy development, and assurance) 1