Easily one of the most useful tools used in public health is the census. It is perhaps the most effective one for public health and public health nurses because the information contained in census data can be used in all areas of public health and in both planning and evaluation of nearly every kind of public health intervention. It can also be used for obtaining adequate funding and for policy development (Krisberg, 2020; Krieger, 2019). Census data is particularly useful for addressing health disparities, reaching underserved communities, and identifying populations which may be at risk for particular conditions. For example, during the Zika virus outbreak of 2015-2016, New York City public health workers used 2010 census data to identify women of childbearing age born in regions affected by Zika who would would be at risk for contracting the virus while traveling to those regions (Krisberg, 2020). Workers then used that information to create targeted public health messaging campaigns aimed at those communities of women (Krisberg, 2020).

Census data is also used to determine the need for other resources, such as schools, roads, and funding for businesses (Krisberg, 2020), which improve access to education, economic stability (via new jobs with easier travel), and potentially healthcare access (via more accessible routes to primary care clinics, etc.). Census data may also be used to improve the process and methods by which data is collected and used, allowing for more accurate representation of underserved communities (Krieger, 2019). For example, issues with the 1840 U.S. census schedule that led to inflated numbers of “insane” black persons in Northern states prompted the Census Board and statistical scholars to redesign the schedule for the 1850 census, allowing for the counting of each person as a single entity, rather than entire households together; this methodology facilitated improved data collection and is still used today (Krieger, 2019).