Accessibility Assessment of WIC Clinics Gerel Oyun PA student GISC 6387 GIS Workshop Summer 2007

About WIC The Special Supplemental Nutrition Program for Women, Infants, and Children, known as WIC The following benefits are provided to WIC participants: Supplemental nutritious foods Nutrition education and counseling Screening and referrals to other health, welfare and social services

About WIC continues The WIC target population are low-income, nutritionally at risk: Pregnant women (through pregnancy and up to 6 weeks after birth or after pregnancy ends). Breastfeeding women (up to infant’s 1st birthday) Non-breastfeeding postpartum women (up to 6 months after the birth of an infant or after pregnancy ends) Infants (up to 1st birthday) Children up to their 5th birthday.

Problem Definition Of those eligible for WIC program 27 percent of infants 33 percent of pregnant and postpartum women 62 percent of children 1–4 do NOT participate. WIC participation is higher in states where program rules require fewer visits, and it is not affected by state-level measures of poverty and unemployment rates. Bitler, M., J. Currie, and J. K. Scholz. (2002). WIC Eligibility and Participation. Institute for Research on Poverty. Discussion Paper no Transportation issue is one of the primary reasons of quitting WIC participation and not collecting WIC vouchers. Rosenberg, T. J., J. K. Alperen, and M. A. Chiasson. (2003). Why Do WIC Participants Fail to Pick Up Their Checks? An Urban Study in the Wake of Welfare Reform. American Journal of Public Health 93: 477–481. Damron, D., P. Langenberg, J. Anliker, M. Ballesteros, R. Feldman, and S. Havas. (1999). Factors associated with attendance in a voluntary nutrition education program. American Journal of Health Promotion13:

Objective and Hypothesis The objective is To identify underserved areas or populations with the purpose of considering for federal and state healthcare resources The hypothesis is that The existing WIC offices provide a full population coverage, and they are located within 30 minutes travel away from the population points.

Definition of Accessibility Accessibility is referred to a measure of the proportion of a population that reaches appropriate health services (WHO, 1998). Accessibility dimensions: Cultural Financial Geographical (WHO, 2000). "The European Observatory on Health Systems and Policies", the glossary of health system related terms used at WHO. Available at:

Traditional Methods Types of spatial accessibility Potential (service availability) Realized (service utilization) Methods provider-to-population ratios distance to nearest provider ( Sometimes referred to as travel cost) average distance to multiple providers gravity models of provider influence Guagliardo, M. F. (2004). Spatial Accessibility of Primary Care: Concepts, Methods and Challenges. International Journal of Health Geographics 3(3). Available from: healthgeographics.com/content/3/1/3 Langford, M., and G. Higgs. (2006). Measuring Potential Access to Primary Healthcare Services: The Influence of Alternative Spatial Representations of Population. The Professional Geographer 58(3):

Provider-to-Population Ratios Ratios compared between small geographic units, such as counties, census tracts or ZIP codes Assumptions are that There is no border crossing All consumers have equal access to health facilities Guagliardo, M. F. (2004). Spatial Accessibility of Primary Care: Concepts, Methods and Challenges. International Journal of Health Geographics 3(3). Available from: healthgeographics.com/content/3/1/3http:// healthgeographics.com/content/3/1/3 Langford, M., and G. Higgs. (2006). Measuring Potential Access to Primary Healthcare Services: The Influence of Alternative Spatial Representations of Population. The Professional Geographer 58(3):

Distance to Nearest Provider Minimum distance in units of Euclidean (straight line) distance, travel distance along a road and/or rail system, or estimated travel time via a transportation network Sometimes referred to as travel cost Weaknesses are: No account of other providers No adjustment for population demand Guagliardo, M. F. (2004). Spatial Accessibility of Primary Care: Concepts, Methods and Challenges. International Journal of Health Geographics 3(3). Available from: healthgeographics.com/content/3/1/3http:// healthgeographics.com/content/3/1/3 Langford, M., and G. Higgs. (2006). Measuring Potential Access to Primary Healthcare Services: The Influence of Alternative Spatial Representations of Population. The Professional Geographer 58(3):

Average Distance to Provider Average distance to nearest x providers, or to all providers within a system (city or county) Weaknesses are: Remote providers inflate the average distance Makes no adjustment for population demand Takes no account of border crossing Guagliardo, M. F. (2004). Spatial Accessibility of Primary Care: Concepts, Methods and Challenges. International Journal of Health Geographics 3(3). Available from: Langford, M., and G. Higgs. (2006). Measuring Potential Access to Primary Healthcare Services: The Influence of Alternative Spatial Representations of Population. The Professional Geographer 58(3):

Gravity Models The potential interaction between any population point and all service points within a reasonable distance Referred to as cumulative opportunity models Weaknesses are: only model supply, no adjustment for demand SA values are unintuitive to healthcare workforce policy makers decay coefficient unknown, and empirical study is needed to estimate β Guagliardo, M. F. (2004). Spatial Accessibility of Primary Care: Concepts, Methods and Challenges. International Journal of Health Geographics 3(3). Available from: Langford, M., and G. Higgs. (2006). Measuring Potential Access to Primary Healthcare Services: The Influence of Alternative Spatial Representations of Population. The Professional Geographer 58(3): Ai is SA from population point Sj is service capacity at provider location j d is the travel distance or travel time, between points i and j. β is a gravity decay coefficient

Data Sources Demographic data from the 2000 Census Summary File 1 Children under 5 Socioeconomic data from the 2000 Census Summary File 3 Population in poverty up to 184 percent of the federal poverty level Female-headed households Women with ages Women with lower educational attainment No schooling completed High school graduate Addresses of WIC clinics from Collin County website. Available at Spatial data from the North Central Texas Council of Governments. Available at

Methodology 1. Define centroid of each census block 2. Define population-weighted centroid of each census block group 3. Show population density map layers 4. Assess spatial accessibility by measuring distance to nearest provider (use the Business Analyst extension) a. Geocode WIC office locations with Create Store Layer b. Create drive-time polygons around each WIC office Use Define Target Area Choose Drive-Time Polygon Specify travel time as 10 minutes, 20 minutes and 30 minutes

Population Density Map Children under 5 Women with ages Female-headed households No schooling completed Poverty up to 184% High school diploma

Car Travel Time to Nearest WIC Office

Characteristics of the Population in Underserved Areas Who are the people currently live in more than 30 minute drive time from the closest WIC office? 5.11% of children under % of women with ages % of women with no schooling completed 20.2% of female high school graduates 20.9% of low-income population 19.8% of female-headed households OR 15% of the target population

Conclusion 1. The target population has less access to WIC clinics than the total population (15% vs. 7.8%). 2. WIC office located in Plano may be experiencing higher volume of clients. 3. WIC participants who have to travel more than 30 minutes should be of matter to federal and state governments. 1. Office locations should be considered to improve spatial accessibility of services: Adding new facilities Moving the existing offices to more convenient locations, such as supermarkets Providing mobile units Recommendations

Study Limitations 1. Assumes that patients would always go to the closest service provider from their residential addresses 2. Assumes that there is no border crossing 3. Takes no account of other providers 4. Makes no adjustment for population demand

Thank You! Comments? Questions? Suggestions?