title: Comparison of geographic methods to assess travel patterns of persons diagnosed with HIV in Philadelphia: how close is close enough?
abstract: Travel distance to medical care has been assessed using a variety of geographic methods. Network analyses are less common, but may generate more accurate estimates of travel costs. We compared straight-line distances and driving distance, as well as average drive time and travel time on a public transit network for 1789 persons diagnosed with HIV between 2010 and 2012 to identify differences overall, and by distinct geographic areas of Philadelphia. Paired t-tests were used to assess differences across methods, and analysis of variance was used to assess between-group differences. Driving distances were significantly longer than straight-line distances (p<0.001) and transit times were significantly longer than driving times (p<0.001). Persons living in the northeast section of the city traveled greater distances, and at greater cost of time and effort, than persons in all other areas of the city (p<0.001). Persons living in the northwest section of the city traveled farther and longer than all other areas except the northeast (p<0.0001). Network analyses that include public transit will likely produce a more realistic estimate of the travel costs, and may improve models to predict medical care outcomes.
authors.affiliation: City of Philadelphia, Philadelphia Department of Public Health, AIDS Activities Coordinating Office, 1101 Market Street, 8th Floor, Philadelphia, PA 19107, USA. Electronic address: michael.eberhart@phila.gov.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Eberhart
authors.affiliation: City of Philadelphia, Philadelphia Department of Public Health, AIDS Activities Coordinating Office, 1101 Market Street, 8th Floor, Philadelphia, PA 19107, USA.
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Share
authors.affiliation: City of Philadelphia, Philadelphia Department of Public Health, AIDS Activities Coordinating Office, 1101 Market Street, 8th Floor, Philadelphia, PA 19107, USA.
authors.forename: Mark
authors.initials: M
authors.lastname: Shpaner
authors.affiliation: City of Philadelphia, Philadelphia Department of Public Health, AIDS Activities Coordinating Office, 1101 Market Street, 8th Floor, Philadelphia, PA 19107, USA.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Brady
mesh_terms: D003625:Data Collection; D040362:Geographic Information Systems; D005843:Geography; D015658:HIV Infections / Q000453:epidemiology* / Q000628:therapy*; D006297:Health Services Accessibility; D006801:Humans; D008490:Medical Informatics / Q000379:methods*; D015143:Philadelphia; D012984:Software; D014186:Transportation; D014195:Travel; D014505:Urban Population
keywords: Geographic Information Systems (GISs); HIV; Network analysis; Travel patterns