healthcare access, ses, and late-stage cancer diagnosis: public policy implications sara mclafferty...
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Healthcare Access, SES, and Late-Stage Cancer Diagnosis: Public Policy
Implications
Sara McLaffertyDepartment of Geography and GIS
University of Illinois at Urbana-Champaign
“On Airs, Waters and Places …”
Hippocrates c. 400 B.C.
Place, space, and health
Places – environments infused with meaning Complex pathways link place characteristics and
health Spatial characteristics of places are important People experience places differently “People create places and places create people”
(MacIntyre and Ellaway 2003)
Crosscutting trends
“New” public health – context, environments• Risky environments
(Rhodes et al. 2005)• Social epidemiology
(Diez Roux 2010)• Built environment
(Hembree et al. 2005)
Data and methods for geographical analysis• Huge increase in spatial
and environmental data• Geographic information
systems (GIS)• Spatial analysis
methods and software
Public Health Spatial Analysis
How can we leverage these trends to enhance cancer control and prevention through effective place-based interventions?
Organization of presentation
Overview of place, space and spatial analysis
Geographic disparities in cancer Geographic foundations for cancer control,
prevention and intervention• Spatial targeting• Spatial tailoring• Spatial generating
Spatial analysis methods: tools for visualizing, analyzing and modeling geospatial information about places
Spatial Data• Information linked to a place (s, y, t)
– Place/location (s)– Attribute (y)– Time (t)
• Spatial data have characteristic geometries
Spatial perspective:
Distance
Pattern
Proximity
Place
Detailed characteristics of people and environment in a locality, and meanings and experiences associated with environment
Spatial analysis methods are used to visualize, explore and model spatial data and their interrelationships
How Chicago would look if % black population had a random spatial distribution
% Black Population
< 20
20 - 40
40 - 60
60 - 80
80 - 100
The actual spatial distribution of % black population shows strong spatial autocorrelation
Low birthweight infants, Brooklyn NY, 2000
Spatial perspectives help us to “see” places more effectively
Kernel Density Estimation
s = k didi<
Where: s = est. density at grid point s di = distance from point i to grid point s = bandwidth k( ) = kernel function
Hotspot mapping
Move a filter across the map
LBW Density, 1.0 mile bandwidth
LBW Density, 2.0 mile bandwidth
How do these concepts relate to cancer research, control, and Intervention?
Cancer Disparities:
“Distinguished by race/ethnicity, gender, age, socioeconomic status, geographic location, occupation, and education, underserved
population groups across the United States suffer disproportionately high cancer incidence and mortality rates for a variety of reasons. These individuals are significantly more likely than the overall U.S.
population to:
Be diagnosed with and die from preventable cancers. Be diagnosed with late stage disease for cancers detectable at an
early stage through screening …”
“Overcoming Cancer Disparities,” http://plan2006.cancer.gov/disparities.shtml
reflecting complex individual, socioeconomic, health care, and environmental factors
Cancer incidence
Screening
Early diagnosis
Treatment
Care
Vary from place to place
Geographic inequalities in cancer incidence:Predicted U.S. cervical cancer incidence (A) and mortality rates (B) by county, 1995 to 2004.
Horner M et al. Cancer Epidemiol Biomarkers Prev 2011;20:591-599
©2011 by American Association for Cancer Research
Geographic inequalities in cancer incidence:Age-adjusted incidence rate of all childhood (ages 0-19) cancers in males by Health Service Area, 1995-2006
Zhu, L., Pickle, LW, Zou, Z, Cucinelli, J. (2014) Trends and patterns of childhood cancer incidence in the United States, 1995-2010. Statistics and its Interface, 7, 121-134.
Spatial filtering reveals geographic variation in colorectal cancer incidence in Iowa
Beyer, K., Tiwari, C., Rushton G. (2012) Five essential properties of disease maps, Annals of the AAG, 102, 1067-75.
Cancer screening varies from place to place
Percent of women ages 18 years and more who reported having had a Papanicolaou smear test within the past 3 years by county—continental United States, 2000 to 2003.
Horner M et al. Cancer Epidemiol Biomarkers Prev 2011;20:591-599
©2011 by American Association for Cancer Research
Strong geographic disparities exist in cancer stage at diagnosis
Late-Stage Breast Cancer Diagnosis varies across Illinois
Mammography facilities are not available in many places of high late-stage risk
Rural-Urban Gradient in Late-stage Cancer
McLafferty S., Wang F. (2009). Rural Reversal? Risk of late-stage cancer across the rural-urban continuum in Illinois. Cancer,
Access to health care resources for cancer screening and treatment is geographically and socially uneven
Uneven Access to Oncologists
And Primary Care Physicians
Onega T. et. al. (2010) Influence of place of residence in access to specialized cancer care for African-Americans. Journal of Rural Health, 26, 12-19.
And access to cancer treatment resources differs socially and spatially: Vulnerable populations often have limited access to, and are less likely to utilize, the most effective cancer treatments
Our research in Illinois shows that places are associated with late-stage cancer via:
Socioeconomic disparities• Low incomes• Vulnerable, high-need populations
Access to primary care services• Only outside Chicago• Transportation barriers
How can we leverage our ability to map, analyze, and understand the
relationships between place, space, and cancer to inform treatment and control policies and interventions?
Geospatial contributions
Spatial (place) targeting Spatial (place) tailoring Spatially generating
Spatial Targeting
Focus resources and interventions to high-prevalence, high-risk places
Methods• Hotspot mapping• Heat mapping• Spatial cluster detection• Risk mapping
Hotspot
Spatial Targeting• Rooted in infectious disease control and eradication
activities• Smallpox eradication (Henderson 1980)
– Disease surveillance– “highly targeted, intensive containment vaccination (p.
426)”
Carter R., Mendis K, Roberts R. (2000) Spatial targeting of interventions against Malaria. Bull World Health Assoc, 78, 1401-1411
Rationale for spatial targeting: Geographically bounded processes
Spatial targeting for other types of health issues
Petersen J. et al. (2009) Teenage pregnancy: New tools to support local health campaigns. Health & Place, 15, 300-307
Rationale is primarily economic
Need to think more critically about spatial targeting• Where to target? Where are the hotspots?• Hotspots are heterogeneous• Hotspots in cold spots• Hidden populations• Stigmatization
Where is the Hotspot?
Clusters of high LBW among infants born to immigrant mothers in Brooklyn & Queens, 2000SaTScan
Clusters of High LBW Among Immigrant Infants
CLUSTER
1
2
0 4 82 Miles
Hotspots are Heterogeneous
0 4 82 Miles
CaribbeanSouth AmericaSouth AsiaMexicoSubSaharan AfricaOther
CaribbeanSouth AmericaSouth AsiaMexicoSubSaharan AfricaOther
Hotspots differ inImmigrant population composition, housing characteristics, population density, access to public transportation
Hot spots within cold spots
% Late-stage breast cancer
diagnosis
Other 32.1%
African-American 45.6%
In small metropolitan areas in Illinois, the risk of late breast cancer diagnosis is low for most women, but very high for African-American women
Hotspots reflect the interlocking effects of people and places
Spatial tailoring
Place-specific customizing of interventions Detailed knowledge of local environment,
people’s livelihoods and economic well-being, sociocultural characteristics, spatial interactions, processes that put people at risk
Place characteristics (people & environment) affect design and implementation• Smallpox eradication, Afghanistan• Not-on-Tobacco, West Virginia (Rothermel et al.
2011)
Kreuter MW, Skinner CS (2000) Tailoring: What’s in a name? Health Educ Res, 15(1), 1-4
Community mapping to support Healthy Start (Aronson et al. 2007)
Examples of place characteristics important for maternal & infant health:
Houses of worshipBusinessesLiquor licensesVacant houses
Aronson RE, Wallis AB, O’Campo PJ, Schafer P (2007). Neighborhood mapping and evaluation: A methodology for participatory community health initiatives. Matern Child Health J, 11, 373-83.
Spatially Generating
Community input in design of interventions• Bottom-up participatory processes• Local knowledge
Participatory GIS (PGIS)
Beyer KMM, Comstock S, Seagren R. (2010) Disease maps as context for community mapping. J Community Health, 33, 635-44.
Colorectal cancer intervention in Storm Lake, IA
Summary
Place matters! Cancer inequalities patterned over space Diverse populations have diverse geographies
and diverse experiences of place Geography affects social interactions,
environmental exposures and access to resources and services
We can leverage these understandings to improve cancer control and prevention through the thoughtful application of strategies of spatial/place targeting, tailoring and generating
THANK YOU!