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1、.,1,Medical Geography: Health Care Accessibility and Implications,Fahui Wang Fred B. Kniffen Professor of Geography Louisiana State University June 17, 2010 CNU,.,2,Contents,The issue of access GIS-based accessibility measures Optimization towards equal access Application in healthcare access PHSA d

2、esignation and late-stage cancer Concluding comments,.,3,Access Matters!,Convenience of access to activities job, school, healthcare, park, public service, shopping Access defines “location” Spatial Where you are Nonspatial Who you are Social justice and public policy,.,4,Measurement,How scarce are

3、the services? Supply vs. Demand (ratio) How far are demands from supplies? Distance Road network Transportation means,.,5,Primitive measures,Distance (time) from supply Simply potential model Supply-demand ratio within an area FCA with a radius/box FCA with a travel time range,.,6,From S/D Ratio to

4、FCA,Simply S/D Ratio FCA with a Radius Improvements Within-unit variation Cross-border Limitations Straight-line S-D beyond radius,.,7,2-step floating catchment area: 2SFCA,Scale availability at each supply location Sum up accessible supplies around each demand location,.,8,2SFCA Recap,1a. For each

5、supply location j, select all demand locations k within a travel time range from j (catchment Cj). 1b. Compute the supply to demand ratio within Cj: 2a. For each demand location i, search all supply locations j within the travel time range from i (catchment Zi). 2b. Sum up the supply to demand ratio

6、s at these supply locations:,.,9,Generalizing “distance decay”,as a continuous function a power or exponential function a Gaussian function as a discrete variable dichotomous as in 2SFCA multiple as in E2SFCA a hybrid approach a kernel density function a three-zone approach,.,10,Generalizing “distan

7、ce decay”,.,11,Validation,Modeling actual supply-demand interactions Individual travel behavior Aggregated travel pattern,.,12,Optimization,Towards equal accessibility Formulated as a planning problem minimizing accessibility gaps among demand locations by adjusting the amounts of supplies at given

8、supply locations.,.,13,A Quadratic Programming Approach,Subject to,where,.,14,Value of optimization,Emphasizing the equality issue Identifying over- and under-capacity of supply Guiding planning and public policy in closing the gap,.,15,Application in Healthcare Access: HPSA designation,U.S. ranks b

9、ehind in health performance deep disparities in access to care and health outcomes Federal programs: MUP & HPSAs Calls for better measure of accessibility,.,16,Non-spatial,Socioeconomic Disadvantages (Factor 1),Socio-cultural Barriers (Factor 2),High Healthcare Needs (Factor 3),Female-headed househo

10、lds (%),Population in poverty (%),Nonwhite minorities (%),Households w/o vehicles (%),Home ownership (%),Households with linguistic isolation (%),Households with 1 person per room (%),Population w/o high-school diploma (%),Median income ($),High needs Population (%),Consolidating nonspatial variable

11、s,.,17,.,18,.,19,.,20,.,21,Integrating Spatial and Nonspatial Factors,Geographic Area Primary Indicator (spatial accessibility score) 1/3500 Primary Indicator (spatial accessibility score) 1/3000 AND secondary indicator (factor 3) 1 standard deviation above mean Population Group Primary Indicator (f

12、actor 1) 1 standard deviation above mean Primary Indicator (factor 1) standard deviation above mean and secondary indicator (factor 2) 1 standard deviation above mean,.,22,.,23,Application in healthcare access (vs. late-stage cancer),.,24,Risk breakdowns,.,25,Culture Knowledge (Dis)advantage Health

13、insurance,Access to primary care Availability and accessibility of screening services Quality of health care,Multilevel approach,Socio-economic disadvantage Social networks and institutions Local resources,PERSON,PLACE,.,26,Rural-urban continuum,Chicago Chicago suburbs Other metro areas Large town (

14、10-50k) Rural,.,27,Multilevel Model Coefficients,.,28,Findings,Effects of individual attributes Older age linked to reduced risk Blacks linked to higher risk Effects of contextual variables Income & primary care access: significant in breast and lung cancer Others: marginally or not significant Effects of urban-rural location,.,29,“urban disadvantage”?,.,30,Public policy implication,.,31,Concluding remarks,Rise of Computational Social Sciences (CSS) and Spatially-integ