Improving an outreach service by analyzing the relationship of health information disparities to socioeconomic indicators using geographic information systems

Abstract

INTRODUCTIONThe use of geographic information systems (GIS) withUS Census data provides libraries with the power tocombine, analyze, and present information in newways. GIS is a valuable tool capable of ‘‘capturing,storing, analyzing, and displaying geographicallyreferenced information’’ [1]. GIS software combinesmaps with layers of associated data to provide avisual picture that allows greater understanding andanalysis than static figures and tables. Although thesoftware was expensive in the past, GIS has becomeincreasingly more affordable for libraries since it hasbecome available in web-based applications, includ-ing open source options [2].Libraries began incorporating US Census data withGIS when the 1990 census materials were given tothe US federal depository libraries as Topological-ly Integrated Geographic Encoding and Reference(TIGER) files [3]. TIGER files are a set of geographicbase files that contain features of the United Statesdown to the street level and census boundaries forcensus statistical areas. TIGER files are designed foruse with GIS software and include geographic codesthat can be linked with demographic and socioeco-nomic data from American Fact Finder (AFF) and theAmerican Community Survey (ACS) [4, 5]. All TIGER,AFF, and ACS files and data are free to the public.Combined with US Census data, GIS is particularlyuseful for libraries in the area of service planning. Forexample, the Public Library Geographic Databasehas compiled US Census demographics on all 16,000public libraries in order to assist decision makers inlibrary planning [6]. Other examples of the use of GISand US Census data include analyzing service mapsfor proposed branches [7], mapping service areas [8],analyzing demographics of populations surroundingthe library [9, 10], analyzing market segmentation[11], and establishing a public library consumer healthcollection [12].In 2011, the Preston Medical Library, in Knoxville,Tennessee, conducted research using GIS and USCensus data. Our goal was to analyze demographicand socioeconomic patterns in order to improvehealth literacy information outreach through our freetelephone-based Consumer and Patient Health Infor-mation Service (CAPHIS). The library’s free tele-phone-based CAPHIS has been in place for overtwo decades, and call data are maintained in an SQLdatabase. The library staff responds to calls to theCAPHIS by mailing packets of health information atthe appropriate literacy level to the caller. The Pres-ton Medical Library provides a useful alternative forthose individuals who do not have Internet access ormay need additional assistance because of limitedhealth literacy and socioeconomic disparities.Several studies have examined the relationship ofsocioeconomic factors and limited health literacy toincreased health costs, chronic disease, and morbidity[13–16]. Health information through libraries is valu-able and can affect consumer health care decisions.Consumers who use libraries for health informationreport positive health actions such as lifestyle changesand compliance with physician instructions [17, 18].However, consumers with low health literacy andcompounding socioeconomic factors are often notaware of the services provided by libraries. Outreachis conducted by libraries to address these disparitiesand provide information services to those surround-ing communities most in need.RESEARCH BACKGROUNDIn 2003, an SQL database was created that containsinformation regarding consumer calls to CAPHIS.Data on calls from 1998 to the present include thecaller’s name, address, and health information re-quest. Although the names and addresses are kept inseparate tables for privacy, the zip codes of theaddresses can be used to establish geographic localitythat can be plotted on a state map and calculated toestablish a rate and area of calls by zip code. Therequested health topics, which are in keyword forminitially, are subsequently indexed by library staffusing the National Library of Medicine’s (NLM’s)Medical Subject Headings (MeSH) in order to becross-referenced with existing information regardingprevalence of diseases in the state that is madeavailable by the Tennessee Department of Health [19].