两步移动搜索法案例(课堂PPT).ppt

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Medical Geography:Health Care Accessibility and Implications,Fahui Wang,Fred B.Kniffen Professor of Geography,Louisiana State University,June 17,2010 CNU,1,Contents,The issue of access,GIS-based accessibility measures,Optimization towards equal access,Application in healthcare access,PHSA designation and late-stage cancer,Concluding comments,2,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,3,Measurement,How scarce are the services?,Supply vs.Demand(ratio),How far are demands from supplies?,Distance,Road network,Transportation means,4,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,5,From S/D Ratio to FCA,Simply S/D Ratio,FCA with a Radius,Improvements,Within-unit variation,Cross-border,Limitations,Straight-line,S-D beyond radius,6,2-step floating catchment area:2SFCA,Scale availability at each supply location,Sum up accessible supplies around each demand location,7,2SFCA Recap,1a.For each supply location,j,select all demand locations k within a travel time range from j(catchment,C,j,).,1b.Compute the supply to demand ratio within,C,j,:,2a.For each demand location,i,search all supply locations j within the travel time range from i(catchment,Z,i,).,2b.Sum up the supply to demand ratios at these supply locations:,8,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,9,Generalizing“,distance decay”,10,Validation,Modeling actual supply-demand interactions,Individual travel behavior,Aggregated travel pattern,11,Optimization,Towards equal accessibility,Formulated as a planning problem,minimizing accessibility gaps,among demand locations by adjusting the amounts of supplies at given supply locations.,12,A Quadratic Programming Approach,Subject to,where,13,Value of optimization,Emphasizing the,equality,issue,Identifying over-and under-capacity of supply,Guiding planning and public policy in closing the gap,14,Application in Healthcare Access:HPSA designation,U.S.ranks behind in health performance,deep,disparities in access to care and health outcomes,Federal programs:MUP&HPSAs,Calls for better,measure of accessibility,15,Non-spatial,Socioeconomic,Disadvantages,(Factor 1),Socio-cultural,Barriers,(Factor 2),High Healthcare,Needs,(Factor 3),Female-headed households(%),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 variables,16,17,18,19,20,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(factor 1)1 standard deviation above mean,Primary Indicator(factor 1)standard deviation above mean and secondary indicator(factor 2)1 standard deviation above mean,21,22,Application in healthcare access(vs.late-stage cancer),Cancer mortality,Late-stage diagnosis,Healthcare access,23,Risk breakdowns,Spatial:where we are,Urban vs.rural,Travel time to cancer screening facility,Access to primary care,Nonspatial:who we are,Individual attributes,Community characteristics(contextual),24,Culture,Knowledge,(Dis)advantage,Health 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,25,Rural-urban continuum,Chicago,Chicago suburbs,Other metro areas,Large town(10-50k),Rural,26,Multilevel Model Coefficients,Breast,Colorectal,Lung,Prostate,Chic_sub,-.181*,-.065*,-.001,-.092*,-.087*,-.029,-.007,-.012,-.017,-.189*,-.105,*,-.062,Other_metro,-.278*,-.146*,-.110*,-.131*,-.122*,-.056,-.172*,-.183*,-.252*,-.128*,-.039,-.012,Large town,-.336*,-.162*,-.167*,-.272*,-.250*,-.198,*,-.331*,-.338*,-.431*,-.191*,-.065,-.063,Rural,-.207*,-.032,-.063,-.169*,-.156*,-.085,-.204*,-.212*,-.323*,-.164*,-.035,-.038,Age50,.547*,.541*,.216*,.216*,.195*,.188*,.129,.128,Age,70,-.279*,-.279*,-.082*,-.083*,-.234*,-.233*,-.174,*,-.177,*,Black,.373*,.370*,.083*,.077*,-.068*,-.085*,.289,*,.,279,*,Income,-.134*,-.047,-.110*,-.087,Non_Engli,.012*,.002,-.001,.003,Access,-37.6*,20.0,-27.2,*,-9.9,Time,.002,0.000,27,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,28,“urban disadvantage”?,29,Public policy implication,How people in particular geographic contexts interact with local health care providers?,30,Concluding remarks,Rise of,Computational,Social Sciences(CSS)and,Spatially,-integrated Social Sciences(SSS),Trends in social sciences,Michael Batty:“to do good,social science,that is,policy,relevant,quantitative methods,are essential and such methods,and the theory behind their practice,must be,spatial,.”,31,