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!