Geospatial analysis of multiple cancers in individuals in the US, 2004-2014.

BACKGROUND: There is a projected rapid increase in cancer survivors in the US population, from 15.5 million in 2016 to 26.1 million by 2040. Improvements in treatment and detection have led to increased survival, however, there is now a risk of developing new cancers as a result of environment toxins, behavioral risk factors, genetic predisposition, and late-term effects of radiation and chemotherapeutic treatments. This study takes a geospatial approach to examining the place of occurrence of multiple cancers originating in the population of four screenable cancers-female breast, colorectal, prostate, and cervical cancers-among the US population. METHODS: During 2004-2014, 6,523,532 primary cancer patients with one of these four screenable cancers were examined, and subsequent primary cancers (multiple cancers of any type) were noted. Individual level analyses estimated the odds of diagnosis with multiple cancers controlling for age, sex, and race-ethnicity. Change in effects on odds of multiple cancer diagnoses with age, sex, and race-ethnicity were evaluated controlling separately for late-stage diagnosis of the primary cancer or each primary cancer diagnosis type. County-level spatial cluster analysis was employed to identify and visualize higher than average multiple cancer rates. RESULTS: Over half of the study population were female and almost 30% of the study population were diagnosed at late-stage for their first cancer. Multiple occurrences of all cancers increased during the time period for patients with initial breast or colorectal cancers. Among BC primary cancer cases, subsequent multiple cancers were mostly new breast cancers. By contrast, for CRC primary cancer cases, subsequent multiple cancers were about equally likely to be new CRC cases or other cancer types. Sex, age and race-ethnicity were all significantly associated with multiple cancers. In the model controlling for CRC as the primary type, the age and race-ethnicity effects were somewhat different than for all the other models. Thus, there was something distinctly different about the multiple cancer incidence among patients with CRC as their primary cancer as compared to patients with BC, CVC, or PC primaries. In subsequent analyses by county, there were distinct geospatial patterns in multiple cancer rates with most high-rate clusters occurring in the north- and mid-west US. CONCLUSIONS: There were distinct individual level and geospatial disparities in multiple cancer diagnoses for the study population of all primary breast, colorectal, cervical, or prostate cancer patients during the decade studied. It is importance to emphasize continued screening for cancer survivors and research on personal and environmental drivers of multiple primary cancers.

Geographic Disparities in Late-Stage Breast Cancer Diagnosis Rates and Their Persistence Over Time.

Background: Other than skin cancer, breast cancer is the most common cancer in the United States. Lower uptake of mammography screening is associated with higher rates of late-stage breast cancers. This study aims to show geographic patterns in the United States, where rates of late-stage breast cancer are high and persistent over time, and examines factors associated with these patterns. Materials and Methods: We examined all primary breast cancers diagnosed among all counties in 43 U.S. states with available data. We used spatial cluster analysis to identify hot spots (i.e., spatial clusters with above average late-stage diagnosis rates among counties). Demographic and socioeconomic characteristics were compared between persistent hot spots and those counties that were never hot spots. Results: Of the 2,599 counties examined in 43 states, 219 were identified as persistent hot spots. Counties with persistent hot spots (compared with counties that were never hot spots) were located in more deprived areas with worse housing characteristics, lower socioeconomic status, lower levels of health insurance, worse access to mammography, more isolated American Indian/Alaska Native, Black, or Hispanic neighborhoods, and larger income disparity. In addition, persistent hot spots were significantly more likely to be observed among poor, rural, African American, or Hispanic communities, but not among poor, rural, White communities. This analysis includes a broader range of socioeconomic conditions than those included in previous literature. Conclusion: We found geographic disparities in late-stage breast cancer diagnosis rates, with some communities experiencing persistent disparities over time. Our findings can guide public health efforts aimed at reducing disparities in stage of diagnosis for breast cancer.

Update on triple-negative breast cancer disparities for the United States: A population-based study from the United States Cancer Statistics database, 2010 through 2014.

BACKGROUND: Triple-negative breast cancer (TNBC) has been associated with a more aggressive histology, poorer prognosis, and nonresponsiveness to hormone therapy. It is imperative that cancer research identify factors that drive disparities and focus on prevention. METHODS: Using the United States Cancer Statistics database, the authors examined differences between TNBCs compared with all other breast cancers with regard to age, race/ethnicity, and stage at diagnosis. RESULTS: A total of 1,151,724 cases of breast cancer were identified from 2010 through 2014, with the triple-negative phenotype accounting for approximately 8.4% of all cases. In unadjusted analyses, non-Hispanic black women (odds ratio [OR], 2.27; 95% CI, 2.23-2.31) and Hispanic women (OR, 1.22; 95% CI, 1.19-1.25) had higher odds of diagnosis when compared with non-Hispanic white women. Women aged <40 years had the highest odds of diagnosis compared with women aged 50 to 64 years (OR, 1.95; 95% CI, 1.90-2.01). Diagnosis at American Joint Committee on Cancer stage III and beyond conferred higher odds of the diagnosis of TNBC (OR for stage III, 1.69 [95% CI, 1.68-1.72]; and OR for stage IV, 1.47 [95% CI, 1.43-1.51]). Results varied slightly in adjusted analyses. CONCLUSIONS: The results of the current study demonstrated that there is a significant burden of disease in TNBC diagnosed among women of color, specifically non-Hispanic black women, and younger women. Additional studies are needed to determine drivers of disparities between race, age, and stage of disease at diagnosis.

What Happened to Disparities in CRC Screening Among FFS Medicare Enrollees Following Medicare Modernization?

The Medicare Modernization Act of 2003, implemented in 2006, increased managed care options for seniors. It introduced insurance plans for prescription drug coverage for all Medicare beneficiaries, whether they were enrolled in FFS or managed care (Medicare Advantage) plans. The availability of drug coverage beginning in 2006 served to free up budgets for FFS Medicare enrollees that could be used to make copayments for colorectal cancer (CRC) screening using endoscopy (colonoscopy or sigmoidoscopy). In 2007, Medicare eliminated the copayments required by seniors for CRC screening by endoscopy. Later in 2008, CRC screening by colonoscopy became part of the gold standard for CRC screening. This legitimized its use and offered even further encouragement to seniors, who may have been reluctant to undergo the procedure because of the non-pecuniary risks associated with it. In addition, 37 CRC screening interventions occurred during this timeframe to enhance compliance with screening standards. Using multilevel analysis of individuals' endoscopy utilization, derived from 100% FFS Medicare claims, along with county-level market and contextual factors, we compare the periods before and after the MMA (2001-2005 to 2006-2009) to determine whether disparities in the utilization of endoscopic CRC screening occurred or changed over the decade. We examined Blacks, Asians, and Hispanics relative to Whites, and Females relative to Males (with race or ethnicity combined). We examined each state separately for evidence of disparities within states, to avoid confounding by geographic disparities. We expected that the net effect of the policy changes and the targeted interventions over the decade would be to increase CRC screening by endoscopy, reducing disparities. We saw improvements over time (reduced disparities relative to Whites) for Blacks and Hispanics residing in several states, and improvements over time for Females relative to Males in many states. For the vast majority of states, however, disparities persisted with Whites and Males exhibiting greater rates of utilization than other groups. States that undertook the interventions were more likely to have had improvements in disparities or positive disparities for women and minorities. While some gains were made over this time period, the gains were unevenly distributed across the USA and more work needs to be done to reduce remaining disparities.

Should Measures of Health Care Availability Be Based on the Providers or the Procedures? A Case Study with Implications for Rural Colorectal Cancer Disparities.

PURPOSE: Patients with colorectal cancer (CRC) living in rural areas have lower survival rates than those in urban areas, potentially because of lack of access to quality CRC screening and treatment. The purpose of this study was to compare traditional physician density (ie, colonoscopy provider availability per capita) against a new physician density measure using an example case of colonoscopy volume and quality. The latter is particularly relevant for rural providers, who may have fewer patients and are more frequently nongastroenterologists. METHODS: We conducted a secondary data analysis of the 2014 Medicare Provider Utilization and Payment Database and the National Cancer Institute State Cancer Profile Database. Volume-weighted physician density scores at the state and county levels were created, accounting for (1) the physician's annual colonoscopy volume and (2) whether the physician performs ≥100 procedures per year. We compared volume-weighted versus traditional density, overall and by rurality, and examined their correlation with CRC screening, incidence, and mortality rates. FINDINGS: The difference between volume-weighted and traditional density scores was particularly large in rural parts of the West and Midwest, and it was most similar in the Northeast. Although weak, correlations with CRC outcomes were stronger for volume-weighted density, and they did not differ by rurality. CONCLUSIONS: Our new method is an improvement over traditional methods because it considers the variation of physician procedure volume, and it has a stronger correlation with population health outcomes. Weighted density scores portray a more realistic picture of physician supply, particularly in rural areas.

Who Performs Colonoscopy? Workforce Trends Over Space and Time.

PURPOSE: With the increased availability of colonoscopy to average risk persons due to insurance coverage benefit changes, we sought to identify changes in the colonoscopy workforce. We used outpatient discharge records from South Carolina between 2001 and 2010 to examine shifts over time and in urban versus rural areas in the types of medical providers who perform colonoscopy, and the practice settings in which they occur, and to explore variation in colonoscopy volume across facility and provider types. METHODS: Using an all-payer outpatient discharge records database from South Carolina, we conducted a retrospective analysis of all colonoscopy procedures performed between 2001 and 2010. FINDINGS: We identified a major shift in the type of facilities performing colonoscopy in South Carolina since 2001, with substantial gains in ambulatory surgery settings (2001: 15, 2010: 34, +127%) versus hospitals (2001: 58, 2010: 59, +2%), particularly in urban areas (2001: 12, 2010: 27, +125%). The number of internists (2001: 46, 2010: 76) and family physicians (2001: 34, 2010: 106) performing colonoscopies also increased (+65% and +212%, respectively), while their annual procedures volumes stayed fairly constant. Significant variation in annual colonoscopy volume was observed across medical specialties (P < .001), with nongastroenterologists having lower volumes versus gastroenterologists and colon and rectal surgeons. CONCLUSIONS: There have been substantial changes over time in the number of facilities and physicians performing colonoscopy in South Carolina since 2001, particularly in urban counties. Findings suggest nongastroenterologists are meeting a need for colonoscopies in rural areas.

Racial and ethnic disparities among state Medicaid programs for breast cancer screening.

Breast cancer screening by mammography has been shown to reduce breast cancer morbidity and mortality. The use of mammography screening though varies by race, ethnicity, and, sociodemographic characteristics. Medicaid is an important source of insurance in the US for low-income beneficiaries, who are disproportionately members of racial or ethnic minorities, and who are less likely to be screened than women with higher socioeconomic statuses. We used 2006-2008 data from Medicaid claims and enrollment files to assess racial or ethnic and geographic disparities in the use of breast cancer screening among Medicaid-insured women at the state level. There were disparities in the use of mammography among racial or ethnic groups relative to white women, and the use of mammography varied across the 44 states studied. African American and American Indian women were significantly less likely than white women to use mammography in 30% and 39% of the 44 states analyzed, respectively, whereas Hispanic and Asian American women were the minority groups most likely to receive screening compared with white women. There are racial or ethnic disparities in breast cancer screening at the state level, which indicates that analyses conducted by only using national data not stratified by insurance coverage are insufficient to identify vulnerable populations for interventions to increase the use of mammography, as recommended.

Modeling Geospatial Patterns of Late-Stage Diagnosis of Breast Cancer in the US.

In the US, about one-third of new breast cancers (BCs) are diagnosed at a late stage, where morbidity and mortality burdens are higher. Health outcomes research has focused on the contribution of measures of social support, particularly the residential isolation or segregation index, on propensity to utilize mammography and rates of late-stage diagnoses. Although inconsistent, studies have used various approaches and shown that residential segregation may play an important role in cancer morbidities and mortality. Some have focused on any individuals living in residentially segregated places (place-centered), while others have focused on persons of specific races or ethnicities living in places with high segregation of their own race or ethnicity (person-centered). This paper compares and contrasts these two approaches in the study of predictors of late-stage BC diagnoses in a cross-national study. We use 100% of U.S. Cancer Statistics (USCS) Registry data pooled together from 40 states to identify late-stage diagnoses among ~1 million new BC cases diagnosed during 2004-2009. We estimate a multilevel model with person-, county-, and state-level predictors and a random intercept specification to help ensure robust effect estimates. Person-level variables in both models suggest that non-White races or ethnicities have higher odds of late-stage diagnosis, and the odds of late-stage diagnosis decline with age, being highest among the

Geospatial Analysis of Inflammatory Breast Cancer and Associated Community Characteristics in the United States.

Inflammatory breast cancer (IBC) is a rare and aggressive form of breast cancer, almost always diagnosed at late stage where mortality outcomes and morbidity burdens are known to be worse. Missed by mammography screening, IBC progresses rapidly and reaches late stage by the time of diagnosis. With an unknown etiology and poor prognosis, it is crucial to evaluate the distribution of the disease in the population as well as identify area social and economic contextual risk factors that may be contributing to the observed patterns of IBC incidence. In this study, we identified spatial clustering of county-based IBC rates among US females and examined the underlying community characteristics associated with the clusters. IBC accounted for ~1.25% of all primary breast cancers diagnoses in 2004-2012 and was defined by the Collaborative Stage (CS) Extension code 710 and 730. Global and local spatial clusters of IBC rates were identified and mapped. The Mann-Whitney U test was used to compare median differences in key contextual variables between areas with high and low spatial clusters of IBC rates. High clusters are counties and their neighbors that all exhibit above average rates, clustered together in a fashion that would be extremely unlikely to be observed by chance, and conversely for low clusters. There was statistically significant evidence of spatial clustering into high and low rate clusters. The average rate in the high rate clusters (n = 46) was approximately 12 times the average rate in low rate clusters (n = 126), and 2.2 times the national average across all counties. Significant differences were found in the medians of the underlying race, poverty, and urbanicity variables when comparing the low cluster counties with the high cluster counties (p < 0.05). Cluster analysis confirms that IBC rates differ geographically and may be influenced by social and economic environmental factors. Particular attention may need to be paid to race, urbanicity and poverty when considering risk factors for IBC and when developing interventions and alternative prevention strategies.

Medicare modernization and diffusion of endoscopy in FFS medicare.

OBJECTIVE: To examine how FFS Medicare utilization of endoscopy procedures for colorectal cancer (CRC) screening changed after implementation of the Medicare Prescription Drug, Improvement, and Modernization Act (MMA) in 2006, which provided subsidized drug coverage and expanded the geographic availability of Medicare managed care plans across the US. DATA SOURCES/STUDY SETTING: Using secondary data from 100% FFS Medicare enrollees, we analyzed endoscopy utilization during two intervals, 2001-2005 and 2006-2009. STUDY DESIGN: We examined change in predictors of county-level endoscopy utilization rates based on a conceptual model of market supply and demand with spillovers from managed care practices. The equations for each period were estimated jointly in a spatial lag regression model that properly accounts for both place and time effects, allowing robust assessment of changes over time. DATA COLLECTION/EXTRACTION METHODS: All Medicare FFS enrollees with both Parts A and B coverage who were age 65+, remained alive and living in the same state over the interval were included in the analyses. The later interval used a new cohort defined the same as the earlier interval. 100% Medicare denominator files were also used, providing county of address to use for county-level aggregation. The outcome variable was defined as county-level proportion of enrollees who ever used endoscopy over the interval. PRINCIPAL FINDINGS: Endoscopy utilization by FFS Medicare increased, and became more accessible across the US. Medicare managed care plan spillovers onto FFS Medicare endoscopy utilization changed over time from a significant negative (restraining) effect in the early period to no significant effect by the later period. CONCLUSIONS: The MMA eased budget constraints for seniors, making endoscopic CRC screening more affordable. The MMA policies also strengthened managed care business prospects, and enrollments in Medicare managed care escalated. The change in managed care spillover effects reflects the gradual acceptance of endoscopic CRC screening procedures, as they emerged as the gold standard during the period.

Breast Cancer Screening Among Women with Medicaid, 2006-2008: a Multilevel Analysis.

INTRODUCTION: Nationally, about one third of women with breast cancer (BC) are diagnosed at late stage, which might be reduced with greater utilization of BC screening. The purpose of this paper is to examine the predictors of BC mammography use among women with Medicaid, and differences among Medicaid beneficiaries in their propensity to use mammography. METHODS: The sample included 2,450,527 women drawn from both fee-for-service and managed care Medicaid claims from 25 states, during 2006-2008. The authors used multilevel modeling of predictors at person, county, and state levels of influence and examined traditional factors affecting access and the expanded scope of practice allowed for the nurse practitioner (NP) in some states to provide primary care independent of physician oversight. RESULTS: Black [OR = 0.87; 95 % CI (0.87-0.88)] and American Indian women [OR = 0.74; 95 % CI (0.71-0.76)] had lower odds ratio of mammography use than white women, while Hispanic [OR = 1.06; 95 % CI (1.05-1.07)] had higher odds ratio of mammography use than white women. Living in counties with higher Hispanic residential segregation [OR = 1.16; 95 % CI (1.10-1.23)] was associated with a higher odds ratio of mammography use compared to areas with low Hispanic residential segregation, whereas living among more segregated black [OR = 0.78; 95 % CI (0.75-0.81)] or Asian [OR = 0.19; 95 % CI (0.17-0.21)] communities had lower odds ratio compared to areas with low segregation. Holding constant statistically the perceived shortage of MDs, which was associated with significantly lower mammography use, the NP regulatory variable [OR = 1.03; 95 % CI (1.01-1.07)] enhanced the odds ratio of mammography use among women in the six states with expanded scope of practice, compared with women residing in 19 more restrictive states. CONCLUSIONS: Racial and ethnic disparities exist in the use of mammography among Medicaid-insured women. More expansive NP practice privileges in states are associated with higher utilization, and may help reduce rural disparities.

Demographic Disparities in Late-Stage Diagnosis of Breast and Colorectal Cancers Across the USA.

BACKGROUND: We determined whether there were disparities in the likelihood of being diagnosed at a late stage for breast cancer (BC) or colorectal cancer (CRC) in each of 40 states, using the recently available US Cancer Statistics (USCS) database. METHODS: We extracted 981,457 BC cases and 558,568 CRC cases diagnosed in 2004-2009. Separate multilevel regressions were run for each state and each cancer type. Models included person and area-level covariates and were identically specified across states. The disparities foci were race or ethnicity (white, African-American, Hispanic, Asian, all other), gender, and age (<40, 40-49, 50-64, 65-74, and 75+). Using whites, males, and the oldest age group as reference groups, we noted the statistically significant disparities coefficients (p value ≤0.05) and translated the findings via a set of maps of states in the USA. RESULTS: National disparity estimates were not consistent with disparities identified in the states. Some states had estimates consistent with the national average, while others did not. Patterns of disparities across states were different for each covariate and mapped separately. CONCLUSION: National disparity estimates may mask what is true at the more local, state level because national estimates can confound the effects of race with place. Cancer control efforts are local and require locally relevant information to assess needs. Findings from the period 2004-2009 establish valuable benchmarks against which to assess changes following national health reform implemented in 2010. The USCS database is a valuable new resource that will facilitate future disparities research.

Using residential segregation to predict colorectal cancer stage at diagnosis: two different approaches.

PURPOSE: Studies have found a variety of evidence regarding the association between residential segregation measures and health outcomes in the United States. Some have focused on any individuals living in residentially segregated places, whereas others have examined whether persons of specific races or ethnicities living in places with high segregation of their own race or ethnicity have differential outcomes. This article compares and contrasts these two approaches in the study of predictors of late-stage colorectal cancer (CRC) diagnoses in a cross-national study. We argue that it is very important when interpreting results from studies like this to carefully consider the geographic scope of the analysis, which can significantly change the context and meaning of the results. METHODS: We use US Cancer Statistics Registry data from 40 states to identify late-stage diagnoses among over 500,000 CRC cases diagnosed during 2004-2009. We pool data over the states and estimate a multilevel model with person, county, and state levels and a random intercepts specification to ensure robust effect estimates. The isolation index of residential segregation is defined for racial and ethnic groups at the county level using Census 2000 data. The association between isolation indices and late-stage CRC diagnosis was measured by (1) anyone living in minority-segregated areas (place-centered approach) and by (2) individuals living in areas segregated by one's own racial or ethnic peers (person-centered approach). RESULTS: Findings from the place-centered approach suggest that living in a highly segregated African American community is associated with lower likelihood of late-stage CRC diagnosis, whereas the opposite is true for people living in highly segregated Asian communities, and living in highly segregated Hispanic communities has no significant association. Using the person-centered approach, we find that living in places segregated by one's racial or ethnic peers is associated with lower likelihood of late-stage CRC diagnosis. CONCLUSIONS: In a model that covers a large geographic area across the nation, the place-centered approach is most likely picking up geographic disparities that may be deepened by targeted interventions in minority communities. By contrast, the person-centered approach provides a national average estimate suggesting that residential isolation may confer community cohesion or support that is associated with better CRC prevention.

How generalizable are the SEER registries to the cancer populations of the USA?

BACKGROUND: We determined whether the current SEER registries are representative of the nation's cancer cases or the socio-demographic characteristics. METHODS: We used breast cancer (BC) and colorectal cancer (CRC) cases diagnosed 2004-2009 from the US Cancer Statistics (USCS) database. Cases were classified into groups residing in SEER coverage areas and the other areas. We compared difference between SEER and non-SEER areas in: age-race-specific proportions of late-stage BC or CRC, area demographics and socioeconomic factors, and data quality. RESULTS: For late-stage CRC diagnosis, SEER areas contained lower proportions of people with other race and higher proportions of Asian and Hispanic females aged <40, than non-SEER areas. For late-stage BC diagnosis, SEER and non-SEER estimates were comparable. SEER areas had lower percentages of whites and higher percentages of young people, were more urban, and had higher percentage of poor, lower educational attainment, and higher unemployment. SEER areas also tended to have a higher percentage of case completeness than non-SEER areas. CONCLUSION: Overall, SEER registries were not significantly different from non-SEER areas in terms of average age-race-specific proportions of late-stage BC or CRC, except for estimates of late-stage CRC for other race and young Asian and Hispanic women. Although case completeness was better in SEER areas than non-SEER areas, SEER areas had greater economic disadvantage and greater minority diversity among the population. This study demonstrated a need for caution in using SEER data and discussed advantages of using the more complete USCS database.

United States Health Policies and Late-stage Breast and colorectal cancer diagnosis: Why such disparities by age?

BACKGROUND: Colorectal and breast cancers are the second most common causes of cancer deaths in the US. Population cancer screening rates are suboptimal and many cancers are diagnosed at an advanced stage, which results in increased morbidity and mortality. Younger populations are more likely to be diagnosed at a later stage, and this age disparity is not well understood. We examine the associations between late-stage breast cancer (BC) and colorectal cancer (CRC) diagnoses and multilevel factors, focusing on individual state regulations of insurance and health practitioners, and interactions between such policies and age. We expect state-level regulations are significant predictors of the rates of late-stage diagnosis among younger adults. METHODS: We included adults of all ages, with BC or CRC diagnosed between 2004 -2009, obtained from a newly available cancer population database covering 98 % of all known new cancer cases. We included personal characteristics, linked with a set of county and state-level predictors based on residence. We applied multilevel models to robustly examine differences in risk of late-stage cancer diagnosis across age groups (defined as age 65+ or < 65), focusing specifically on the effects of state regulatory factors and their interactions with age. RESULTS: Late stage BC diagnoses range from 24 %-36 %, while CRC diagnoses range from 54 %-60 % of newly diagnosed BC or CRC cases across states. After controlling statistically for many confounding factors at three levels, age < 65 is the largest person-level predictor for CRC, while black race is the largest predictor for BC. State regulations of health markets exhibit significant interactions with age groups. CONCLUSIONS: The state regulatory climate is an important predictor of late-stage BC and CRC diagnoses, especially among people younger than Medicare eligible age (65). State regulations can enhance the climate of access for younger, less well-insured or uninsured persons who fall outside normative screening guidelines.

Geographic and Demographic Disparities in Late-stage Breast and Colorectal Cancer Diagnoses Across the US.

PROBLEM: In 2009, breast cancer was the most common cancer in women, and colorectal cancer was the third most common cancer in both men and women. Currently, the majority of colorectal and almost 1/3 of breast cancers are diagnosed at an advanced stage in the US, which results in higher morbidity and mortality than would obtain with earlier detection. The incidence of late-stage cancer diagnoses varies considerably across the US, and few analyses have examined the entire US. PURPOSE: Using the newly available US Cancer Statistics database representing 98% of the US population, we perform multilevel analysis of the incidence of late-stage cancer diagnoses and translate the findings via bivariate mapping, answering questions related to both Why and Where demographic and geographic disparities in these diagnoses are observed. METHODS: To answer questions related to Why disparities are observed, we utilize a three-level, random-intercepts model including person-, local area-, and region- specific levels of influence. To answer questions related to Where disparities are observed, we generate county level robust predictions of late-stage cancer diagnosis rates and map them, contrasting counties ranked in the upper and lower quantiles of all county predicted rates. Bivariate maps are used to spatially translate the geographic variation among US counties in the distribution of both BC and CRC late-stage diagnoses. CONCLUSIONS: Empirical modeling results show demographic disparities, while the spatial translation of empirical results shows geographic disparities that may be quite useful for state cancer control planning. Late stage BC and CRC diagnosis rates are not spatially random, manifesting as place-specific patterns that compare counties in individual states to counties across all states. Providing a relative comparison that enables assessment of how results in one state compare with others, this paper is to be disseminated to all state cancer control and central cancer registry program officials.

Spatial analysis of HIV positive injection drug users in San Francisco, 1987 to 2005.

Spatial analyses of HIV/AIDS related outcomes are growing in popularity as a tool to understand geographic changes in the epidemic and inform the effectiveness of community-based prevention and treatment programs. The Urban Health Study was a serial, cross-sectional epidemiological study of injection drug users (IDUs) in San Francisco between 1987 and 2005 (N = 29,914). HIV testing was conducted for every participant. Participant residence was geocoded to the level of the United States Census tract for every observation in dataset. Local indicator of spatial autocorrelation (LISA) tests were used to identify univariate and bivariate Census tract clusters of HIV positive IDUs in two time periods. We further compared three tract level characteristics (% poverty, % African Americans, and % unemployment) across areas of clustered and non-clustered tracts. We identified significant spatial clustering of high numbers of HIV positive IDUs in the early period (1987-1995) and late period (1996-2005). We found significant bivariate clusters of Census tracts where HIV positive IDUs and tract level poverty were above average compared to the surrounding areas. Our data suggest that poverty, rather than race, was an important neighborhood characteristic associated with the spatial distribution of HIV in SF and its spatial diffusion over time.

The small area predictors of ambulatory care sensitive hospitalizations: a comparison of changes over time.

The hospital admission for ambulatory care sensitive conditions (ACSCs) is a validated indicator of impeded access to good primary and preventive care services. The authors examine the predictors of ACSC admissions in small geographic areas in two cross-sections spanning an 11-year time interval (1995-2005). Using hospital discharge data from the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality for Arizona, California, Massachusetts, Maryland, New Jersey, and New York for the years 1995 and 2005, the study includes a multivariate cross-sectional design, using compositional factors describing the hospitalized populations and the contextual factors, all aggregated at the primary care service area level. The study uses ordinary least squares regressions with and without state fixed effects, adjusting for heteroscedasticity. Data is pooled over 2 years to assess the statistically significant changes in associations over time. ACSC admission rates were inversely related to the availability of local primary care physicians, and managed care was associated with declines in ACSC admissions for the elderly. Minorities, aged elderly, and percent under federal poverty level were found to be associated with higher ACSC rates. The comparative analysis for 2 years highlights significant declines in the association with ACSC rates of several factors including percent minorities and rurality. The two policy-driven factors, primary care physician capacity and Medicare-managed care penetration, were not found significantly more effective over time. Using small area analysis, the study indicates that improvements in socioeconomic conditions and geographic access may have helped improve the quality of primary care received by the elderly over the last decade, particularly among some minority groups.

Macro-level factors impacting geographic disparities in cancer screening.

OBJECTIVES: Examine how differences in state regulatory environments predict geographic disparities in the utilization of cancer screening. DATA SOURCES/SETTING: 100% Medicare fee-for-service population data from 2001-2005 was developed as multi-year breast (BC) and colorectal cancer (CRC) screening utilization rates in each county in the US. STUDY DESIGN: A comprehensive set of supply and demand predictors are used in a multilevel model of county-level cancer screening utilization in the context of state regulatory markets. States dictate insurance mandates/regulations and whether alternative providers (nurse practitioners) can provide preventive care services supplied by MDs. Controlling statistically for the supply of both types of providers, we study the joint effects of two private insurance regulations: one mandating that insureds with serious or chronic health conditions may receive continuity of care from their established physician(s) after changing health insurance plans, and another mandating that external grievance review is an option for all health plan coverage/denial decisions. These private insurance plan regulations are expected to affect the degree of beneficial spillovers from managed care practices, which may have increased area-wide cancer screening rates. PRINCIPAL FINDINGS: The two private insurance regulations under study were significant predictors impacted by local market conditions. Managed care spillovers in local markets were significantly associated with higher BC screening rates, but only in states lacking the two forms of regulation under study. Spillovers were significantly associated with higher CRC cancer screening rates everywhere, but much higher in the unregulated states. Area poverty dampened screening rates, but less so for CRC screening in the states with these regulations. CONCLUSIONS: Two state insurance regulations that empowered consumers with more autonomy to make informed utilization decisions varied across states, and exhibited significant associations with screening rates, which varied with the degree of managed care penetration or poverty in the state's counties. Beneficial spillover effects from managed care practices and negative influences from area poverty are not uniform across the United States. Both variables had stronger associations with CRC than BC screening utilization, as did state regulatory variables. CRC screening by endoscopy was more subject to market and regulatory factors than BC screening.

Changes in the health care safety net 1992-2003: disparities in access for uninsured persons in Florida.

A patchwork of services is available to uninsured in the United States through the health care safety net. During 1996-2003, some safety net hospitals (SNHs) closed or converted their ownership status from public or non-profit to for-profit. Meanwhile, the number of community health centers (CHCs) grew as a result of new federal funding. This article examines the impact of these two countervailing events on access to care for the uninsured. Hospital admissions for ambulatory care sensitive conditions relative to marker conditions were used as our access measure. We examined 35,730 discharges for uninsured adults treated in Florida hospitals in the years 1992 or 2003. A generalized estimating equation model was used to assess differential access effects for racial and ethnic groups. We found that in communities with CHC openings but no SNH contractions, uninsured black and white individuals experienced deteriorations in access over time, but the Hispanic uninsured did not. However, in communities where SNHs closed or converted, access deteriorations occurred for all three racial and ethnic groups. Thus, the potentially beneficial effects of CHC expansions on access to primary care for the uninsured Hispanic population in Florida appeared to be offset if contractions in the hospital safety net were present.