Comparing Alternative Methods of Measuring Geographic Access to Health Services

AbstractObjective: This research compared alternative measures of geographic access to health care providers using different levels of spatial aggregation (county, zipcode and street) and different methods of calculating the cost of space (Euclidean distance, road distance and travel time). Data Sources: The research is based on a community-based sample of rural (74%) and urban (26%) Arkansans (n=435) and all medical providers (n=3,419) and mental health specialists (n=1,034) practicing in the state of Arkansas in 1993. Study Design: A cross-sectional study design was used to determine the availability of and accessibility to general medical and specialty mental health providers. Accessibility was defined as the travel time between each subject and the closest provider. Availability was defined as the number of providers within 30 minutes travel time of each subject. Data Collection: A Geographic Information System was used to geocode subjects and providers at the county, zip code and street levels, and to calculate the travel times, road distances and Euclidean distances between subjects and providers. Principal Findings: Regression results demonstrated that the most commonly used county-based measures of geographic access (e.g., MSA designation and providers per capita) explained 3%–10% of the variation in accessibility and 34%–70% of the variation in availability. Conclusions: Results indicate that Geographic Information Systems can be used to accurately measure geographic access to health services in a cost effective manner.

[1]  Harold S. Luft,et al.  Correlation of Travel Time on Roads versus Straight Line Distance , 1995, Medical care research and review : MCRR.

[2]  J Fortney,et al.  The impact of geographic accessibility on the intensity and quality of depression treatment. , 1999, Medical care.

[3]  E. Fisher,et al.  The distance to community medical care and the likelihood of hospitalization: is closer always better? , 1997, American journal of public health.

[4]  J. Fortney,et al.  Rural-urban differences in depression treatment and suicidality. , 1998, Medical care.

[5]  L. Møller-Jensen,et al.  Towards a framework for delineating sub-districts for primary health care administration in rural Ghana: A case study using GIS , 2001 .

[6]  A. S. Bhalla.  Access to Health Services , 1991 .

[7]  R. Penchansky,et al.  The Concept of Access: Definition and Relationship to Consumer Satisfaction , 1981, Medical care.

[8]  I. Jacoby.  Geographic Distribution of Physician Manpower: the GMENAC Legacy* , 1991 .

[9]  Jack Brimberg,et al.  A New Distance Function for Modeling Travel Distances in a Transportation Network , 1992, Transp. Sci..

[10]  John Bound,et al.  On the Validity of Using Census Geocode Characteristics to Proxy Individual Socioeconomic Characteristics , 1995 .

[11]  D. Makuc,et al.  Travel for Ambulatory Medical Care , 1983, Medical care.

[12]  L. Anselin.  Spatial Econometrics: Methods and Models , 1988 .

[13]  W M Gesler,et al.  Normative models and healthcare planning: network-based simulations within a geographic information system environment. , 1997, Health services research.