Jonathan D. Mayer

Geography, ecology and emerging infectious diseases

Emerging infectious diseases are the focus of increased attention and even alarm in the scholarly and popular literature. The emergence of new diseases and the resurgence of older and previously recognized infectious diseases both in developing and developed country poses challenges for understanding the ecological web of causation, including social, economic, environmental and biological components. This paper is a synthesis of the major characteristics of emerging diseases, in an interdisciplinary context. Political ecology is one framework for analysis that is promising in developing a modified ecology of disease.

The role of spatial analysis and geographic data in the detection of disease causation

Spatial analyses of disease patterns have been used by investigators as one tool with which to address problems of disease causation. However, while the results of spatial studies may be suggestive, they have been definitive only rarely. This is because there are numerous epistemological, logical and methodological problems which are encountered in spatial analysis. It is important to address these problems as one step in answering the basic issues concerning the role of spatial analysis in the detection of disease causation.

Associations Between Residential Segregation and Smoking During Pregnancy Among Urban African-American Women

Approximately 10% of African-American women smoke during pregnancy compared to 16% of White women. While relatively low, the prevalence of smoking during pregnancy among African-American women exceeds the Healthy People 2010 goal of 1%. In the current study, we address gaps in extant research by focusing on associations between racial/ethnic residential segregation and smoking during pregnancy among urban African-American women. We linked measures of segregation to birth certificates and data from the 2000 census in a sample of US-born African-American women (n = 403,842) living in 216 large US Metropolitan Statistical Areas (MSAs). Logistic regression models with standard errors adjusted for multiple individual observations within MSAs were used to examine associations between segregation and smoking during pregnancy and to control for important socio-demographic confounders. In all models, a u-shaped relationship was observed. Both low segregation and high segregation were associated with higher odds of smoking during pregnancy when compared to moderate segregation. We speculate that low segregation reflects a contagion process, whereby salutary minority group norms are weakened by exposure to the more harmful behavioral norms of the majority population. High segregation may reflect structural attributes associated with smoking such as less stringent tobacco control policies, exposure to urban stressors, targeted marketing of tobacco products, or limited access to treatment for tobacco dependence. A better understanding of both deleterious and protective contextual influences on smoking during pregnancy could help to inform interventions designed to meet Healthy People 2010 target goals.

Patterns of rural hospital closure in the United States

This is a case-control study of rural hospitals which closed between 1970 and 1980. Nonmetropolitan hospitals which closed were matched with a comparable set of hospitals which remained open, yielding 148 closures (cases) and 310 controls. Univariate and multivariate analyses indicate that closed hospitals differ from open hospitals in their internal characteristics, and that their geographical service areas also are significantly different. At the multivariate level, the most significant variables, as determined by stepwise discriminant analysis, are the ownership (profit) status of the hospital, occupancy rate, competitive beds within the county, scope of service, and county population change during the preceding decade. The nature of the discriminant functions differed between counties which were adjacent to metropolitan areas, and those which were not adjacent to metropolitan areas. Closed hospitals differ from open hospitals, as ascertained by standard data sources. Hospital closure reflects the interaction of internal hospital characteristics, and the characteristics of the hospitals service area.

The distance behavior of hospital patients: A disaggregated analysis☆

Regional health systems planning implicitly incorporates information about the distance behavior of hospital patients, in specifying hospital catchment areas, service-specific catchment areas and levels of centralization. Distance behavior of patients varies depending on their diagnoses and on the treatment and diagnostic procedure(s). In this study, a variety of procedures, ranging from those which are routine to those which are highly specialized, are analyzed within the framework of distance behavior. Regionalization of selected services will, by definition, affect distance behavior.

Paramedic response time and survival from cardiac arrest

Abstract It has been assumed in the past that minimizing response time is an important goal in emergency medical services (EMS) systems planning. However, this assumption has yet to be proven. In this analysis, 525 cardiac arrest cases are examined and the relationship between response time and survival determined. Paramedic response time is confirmed to be related statistically to long and short term survival from ventricular fibrillation.

Challenges to understanding spatial patterns of disease: Philosophical alternatives to logical positivism

Most studies of disease distribution, in medical geography and other related disciplines, have been empirical in nature and rooted in the assumptions of logical positivism. However, some of the more newly articulated philosophies of the social sciences, and of social theory, have much to add in the understanding of the processes and mechanisms underlying disease distribution. This paper represents a plea for creative synthesis between logical positivism and realism or structuration, and uses specific examples to suggest how disease distribution, as a surface phenomenon, can be explained using deeper analysis.

Area-based socio-economic disadvantage and tuberculosis incidence.

OBJECTIVE To examine neighborhood-level influences on tuberculosis (TB) incidence in a multilevel population-based sample. DESIGN All incident TB cases in Washington State, United States (n = 2161), reported between 1 January 2000 and 31 December 2008 were identified. Multivariate Poisson analysis was used at the ZIP Code tabulation area (ZCTA) level, which allowed for further exploration of area-specific influences on TB incidence. RESULTS A significant association was found between indices of socio-economic position (SEP) and TB incidence in Washington State, with a clear gradient of higher rates observed among lower ZCTA socio-economic quartiles. Compared to the wealthiest SEP quartile, the relative incidence of TB in successively lower quartiles was respectively 2.7, 4.1 and 10.4 (P trend <0.001). In multivariate analyses, the addition of area-level race, ethnicity and country of birth significantly attenuated this association (adjusted incidence rate ratios 2.3, 2.6, 5.7; P trend <0.001). CONCLUSION This study found a significant inverse association between area measures of socio-economic status (SES) and TB incidence across ZCTAs in Washington State, even after adjusting for individual age and sex and area-based race, ethnicity and foreign birth. These results emphasize the importance of neighborhood context and the need to target prevention efforts to low-SES neighborhoods.

Fine particulate matter exposure and initial Pseudomonas aeruginosa acquisition in cystic fibrosis.

RATIONALE Increasing evidence suggests that exposure to ambient air pollution contributes to the severity of cystic fibrosis (CF) respiratory disease in school-age children and adults; however, the effects of air pollution on young children with CF are poorly understood. OBJECTIVES To investigate the association of exposure to fine particulate matter less than 2.5 μm in aerodynamic diameter (PM2.5) and initial Pseudomonas aeruginosa acquisition in young children with CF. METHODS Retrospective analysis of initial Pseudomonas acquisition in children 6 years of age or younger, using Cystic Fibrosis Foundation National Patient Registry data from 2003 to 2009. PM2.5 exposure was estimated by inverse distance weighting methods based on air pollution monitors within 30 miles of place of residence, for the year before the patients birth. Multivariable Weibull regression with interval-censored outcomes was done to evaluate the association of time to initial Pseudomonas acquisition and PM2.5 concentrations. MEASUREMENTS AND MAIN RESULTS A total of 3,575 children met inclusion criteria and 48% (n=1,711) acquired Pseudomonas at a median age of 15 months (25th-75th percentiles, 9-25 mo). An increase in PM2.5 exposure of 10 μg/m3 was associated with a 24% increased risk of Pseudomonas acquisition (95% confidence interval, 1-51%) during follow-up. Results were generally consistent across exposure metrics. CONCLUSIONS These results suggest that increased PM2.5 exposure is associated with earlier Pseudomonas acquisition in young children with CF and may play an important, previously unrecognized, role in the etiology of initial Pseudomonas infection.

Differential Geographical Risk of Initial Pseudomonas aeruginosa Acquisition in Young US Children With Cystic Fibrosis

Pseudomonas aeruginosa is the sentinel respiratory pathogen in cystic fibrosis patients. We conducted a retrospective study to examine whether state of residence affected risk of P. aeruginosa acquisition among US children under 6 years of age with cystic fibrosis by using data from the Cystic Fibrosis Foundation National Patient Registry, 2003-2009. The outcome was time to first isolation of P. aeruginosa from a respiratory culture. We used a Bayesian hierarchical Weibull regression model with interval-censored outcomes. Spatial random effects, included at the state level and modeled using an intrinsic conditional autoregressive prior, allowed estimation of the residual spatial correlation. The regression portion of the model was adjusted for demographic and disease characteristics potentially affecting P. aeruginosa acquisition. A total of 3,608 children met the inclusion criteria and were followed for an average of 2.1 (standard deviation, 1.6) years. P. aeruginosa was cultured in 1,714 (48%) subjects. There was a moderately elevated spatial residual relative risk. An estimated 95% credible interval for the residual hazard ratio under 1 of the fitted models was 0.64-1.57; the strongest positive association was observed in the Southern states. The fact that risk for P. aeruginosa acquisition displayed spatial dependence suggests that regional factors, such as climate, may play an important role in P. aeruginosa acquisition.