Geography of health: some trends and perspectives

Geospatial evaluation of COVID-19 mortality: Influence of socio-economic status and underlying health conditions in contiguous USA

Since its outbreak, COVID-19 disease has claimed over one hundred thousand lives in the United States, resulting to multiple and complex nation-wide challenges. In this study, we employ global and local regression models to assess the influence of socio-economic and health conditions on COVID-19 mortality in contiguous USA. For a start, stepwise and exploratory regression models were employed to isolate the main explanatory variables for COVID-19 mortality from the ensemble 33 socio-economic and health parameters between January 1st and 16th of September 2020. Preliminary results showed that only five out of the examined variables (case fatality rate, vulnerable population, poverty, percentage of adults that report no leisure-time physical activity, and percentage of the population with access to places for physical activity) can explain the variability of COVID-19 mortality across the Counties of contiguous USA within the study period. Consequently, we employ three global and two local regression algorithms to model the relationship between COVID-19 and the isolated socio-economic and health variables. The outcomes of the regression analyses show that the adopted models can explain 61%-81% of COVID-19 mortality across the contiguous USA within the study period. However, MGWR yielded the highest R2 (0.81) and lowest AICc values (4031), emphasizing that it is the most efficient among the adopted regression models. The computed average adjusted R2 values show that local regression models (mean adj. R2 = 0.80) outperformed the global regression models (mean adj. R2 = 0.64), indicating that the former is ideal for modeling spatial causal relationships. The GIS-based optimized cluster analyses results show that hotspots for COVID-19 mortality as well as socioeconomic variables are mostly delineated in the South, Mid-West and Northeast of contiguous USA. COVID-19 mortality exhibited positive and significant association with black race (0.51), minority (0.48) and poverty (0.34). Whereas, the percentage of persons that attended college was negatively associated with poverty (-0.51), obesity (-0.50) and diabetes (-0.45). Results show that education is crucial to improve socio-economic and health conditions of the Americans. We conclude that investing in people's standard of living would reduce the vulnerability of an entire population.

Analysis of Patient Visits and Collections After Opening a Satellite Pediatric Emergency Department

OBJECTIVE

Satellite pediatric emergency departments (PEDs) have emerged as a strategy to increase patient capacity. We sought to determine the impact on patient visits, physician fee collections, and value of emergency department (ED) time at the primary PED after opening a nearby satellite PED. We also illustrate the spatial distribution of patient demographics and overlapping catchment areas for the primary and satellite PEDs using geographical information system.

METHODS

A structured, financial retrospective review was conducted. Aggregate patient demographic data and billing data were collected regarding physician fee charges, collections, and patient visits for both PEDs. All ED visits from January 2009 to December 2013 were analyzed. Geographical information system mapping using ArcGIS mapped ED patient visits.

RESULTS

Patient visits at the primary PED were 53,050 in 2009 before the satellite PED opened. The primary PED visits increased after opening the satellite PED to 55,932 in 2013. The satellite PED visits increased to 21,590 in 2013. Collections per visit at the primary PED decreased from $105.13 per visit in 2011 to $86.91 per visit in 2013. Total collections at the satellite PED decreased per visit from $155.41 per visit in 2011 to $128.53 per visit in 2013.

CONCLUSIONS

After opening a nearby satellite PED, patient visits at the primary PED did not substantially decrease, suggesting that there was a previously unrecognized demand for PED services. The collections per ED visit were greater at the satellite ED, likely due to a higher collection rate.

Epidemiologic-Ecological Models of Aging

Model building in epidemiological-ecologic research on aging is hampered by the prevailing paradigm of standard empiricism, lack of knowledge about the biological origins and causes of aging and problems in differentiating the aging process from age-related diseases and disabilities. Consequently, the identification of associations or causal relations between risk factors, aging, diseases and disabilities suffers from a number of conceptual and methodological problems which sometimes can lead to research results which are absurd in the context of real life despite their formal correctness. The benefit of building theoretical models arises out of the necessity to construct an empirically sensible order of events which renders the research object intelligible. It is suggested that in the multifactorial epidemiological-ecologic aging research it might be useful to adopt and empirically test the concept of the “effective causal complex” instead of continuing, in many cases fruitless, attempts to define the effects of single risk factors on the associations between aging, physiological damage and disease and disability outcomes.

Implantação do Programa Saúde da Família e exclusão sócio-espacial no Município de São Paulo, Brasil

O presente artigo analisa o processo de implantação do Programa Saúde da Família (PSF) na capital paulista, tomando por referência a construção do espaço urbano, caracterizado por forte segregação sócio-espacial. Os 96 Distritos Administrativos foram divididos em cinco estratos a partir de sua inserção no ranking do Mapa da Exclusão Social. A cobertura populacional, a maturidade do PSF e a caracterização da natureza jurídico-institucional das instituições parceiras foram identificadas. Com base nos resultados, foi elaborada uma tipologia da implantação do PSF pelos estratos. A implantação do PSF é heterogênea, consolidada apenas nos estratos de maior exclusão, indicando tensão com o discurso da Secretaria Municipal de Saúde, segundo o qual o PSF é modelo de atenção para o conjunto da cidade e com foco inicial na população-alvo com renda de até cinco salários mínimos. Há menor cobertura da população-alvo residente nos estratos superiores, evidenciando um constrangimento para alcançá-la na cidade como um todo. As instituições religiosas estão situadas nos estratos com maior exclusão, aqueles com alta cobertura e maior maturidade, caracterizando um tipo de inserção espacial distinto daquele das instituições universitárias.

[Spacial modeling of cutaneous leishmaniasis risk zones]

OBJECTIVE

To spatially delimit cutaneous leishmaniasis (CL) human contact risk zones (CoRZ) using remote sensing and geoprocessing techniques.

METHODS

A total of 27 CL cases reported from 1992 to 1997 in the municipality Itapira, Brazil, were studied. The influence of some important environmental variables related to CL such as altitude and vegetation density measured by normalized difference vegetation index (NDVI) images were analyzed for each CoRZ.

RESULTS

The results showed that about 50% of the dwellings where CL cases were reported were located less than 200 meters from the limits of forest remnant area; more than 70% of the total area of the CoRZ, for each criterion, were in altitudes lower than 750 meters; and about 50% of the CoRZ, for each criterion, were located in a very dense green area (NDVI ranging from 0.45 to 1.00).

CONCLUSIONS

The study shows there may be three transmission modes in the study area: intra-forest, extra-forest (in this setting, transmission might be influenced by the vegetation density surrounding forest remnants); or domiciliary.

Spatial and temporal analysis of the distribution of hantavirus pulmonary syndrome in Buenos Aires Province, and its relation to rodent distribution, agricultural and demographic variables

We studied the spatial and temporal distribution of Hantavirus Pulmonary Syndrome (HPS) cases from 1998 to 2001 in the Buenos Aires Province, Argentina. HPS is a severe viral disease whose natural reservoir are rodents of the subfamily Sigmodontinae (Muridae) and which occurs in many countries of South and North America. We considered two spatial arrangements: cells of 18.5 x 18.5 km(2); and departments, the political subdivisions of the province, as spatial units. We tested the departure from a Poisson distribution of the number of cases per cell and per month with the Variance/Mean index, while the interaction between spatial and temporal clustering was tested by means of the Knox and Mantel tests. We constructed probability maps in which the HPS rates per department were considered Poisson variates according to population, area and the product of population and area. We analysed the relation between rodent distribution, environmental and demographic variables and HPS cases conducting preliminary univariate analysis from which we selected variables to enter in general linearized models. We found that both the spatial and temporal distribution of cases is strongly aggregated. The spatiotemporal interaction appears to be related to a strong seasonality and the existence of particular ecological conditions rather than epidemic transmission of the disease. The main explanatory variables for the distribution of HPS cases among the departments of the Buenos Aires Province were human population, the distribution of the rodent Oxymycterus rufus and evapotranspiration. The last two variables are probably indicators of favourable ecological conditions for the reservoirs, which encompass other variables not taken into account in this study.

New perspectives on the use of Geographical Information Systems (GIS) in environmental health sciences

At first glance, the domain of health is no typical area to applicate Geographical Information Systems (GIS). Nevertheless, the recent development clearly shows that also within the domains of environmental health, disease ecology and public health GIS have become an indispensable tool for processing, analysing and visualising spatial data. In the field of geographical epidemiology, GIS are used for drawing up disease maps and for ecological analysis. The striking advantages of GIS for the disease mapping process are the considerably simplified generation and variation of maps as well as a broader variety in terms of determining a real units. In the frame of ecological analysis, GIS can significantly assist with the assessment of the distribution of health-relevant environmental factors via interpolation and modelling. On the other hand, the GIS-supported methods for the detection of striking spatial patterns of disease distribution need to be much improved. An important topic in this respect is the integration of the time dimension. The increasing use of remote sensing as well as the integration into internet functionalities will stimulate the application of GIS in the field of Environmental Health Sciences (EHS). In future, the integration and analysis of health-relevant data in one single data system will open up many new research opportunities.

Mapping adolescent health and lifestyles in a multi-state country: methodological aspects and first results

OBJECTIVES

To explore the feasibility of a geographical analysis (mapping) of data from a national adolescent survey.

METHODS

Teenagers 15 to 19 years in high school or apprenticeship (N = 5275 boys and 3993 girls) answered a self-administered anonymous questionnaire targeting health and lifestyles. Switzerland was divided in 14 subunits, each one including at least 400 subjects: large cantons were isolated by themselves whereas smaller ones were aggregated taking into account common cultural, geographical and health characteristics. To minimize the impact of sample differences across the cantons, subsamples were weighted according to age, sex, and professional background. For each variable, the discretization of the values in five classes was performed using the threshold approach which maximizes intergroup differences and minimizes the intragroup differences.

RESULTS

The analysis suggests different patterns of distribution depending on the type of variable studied: substance use differs mostly between urban and rural cantons, while mental health differs between French and German-speaking cantons.

CONCLUSIONS

Whereas most available atlases are derived from population-based data (i.e., mortality rates), this research demonstrates the feasibility of using self-reported data from school-based survey samples. The presentation of data on attractive maps provides a unique opportunity for generating hypotheses as to the causes of differences across cantons in a multi-ethnic, multicultural country.

Physical access to primary health care in Andean Bolivia

Limited physical access to primary health care is a major factor contributing to the poor health of populations in developing countries, particularly in mountain areas with rugged topography, harsh climates and extensive socioeconomic barriers. Assessing physical access to primary health care is an important exercise for health care planners and policy makers. The development of geographic information system (GIS) technology has greatly improved this assessment process in industrialized countries where digital cartographic data are widely available. In developing countries particularly in mountain areas, however, detailed cartographic data, even in hardcopy form, are nonexistent, inaccurate or severely lacking. This paper uses GIS technology to assess physical access to primary health care in a remote and impoverished region of Andean Bolivia. In addition, it proposes an alternative model of health personnel distribution to maximize physical accessibility. Methods involved extensive fieldwork in the region, utilizing GPS (global positioning system) technology in the development of the GIS and gathering other pertinent health data for the study. Satellite imagery also contributed to the development of the GIS and in the modeling process. The results indicate significant variation in physical access to primary health care across the three study sites. More importantly, this paper highlights the use of GIS technology as a powerful tool in improving physical accessibility in mountain areas of developing countries.

Transitions and inequalities in acute myocardial infarction mortality in New South Wales, 1969-94

OBJECTIVE

To chart the transition in myocardial infarction mortality in NSW between 1969 and 1994 and to determine whether spatial, marital and occupational status differentials increased over time, despite overall mortality decline.

METHOD

The study was undertaken in NSW for the 25-year period from 1969 when mortality from ischaemic heart disease declined. The demographic and spatial analysis involved descriptive epidemiology and utilised the unit list mortality files of the Australian Bureau of Statistics which are based on detailed death certificate information.

RESULTS

Spatial, marital and occupational status differentials in myocardial infarction mortality increased over time, more especially variations by occupational status, inland/metropolitan differences, and married/divorced or widowed variation. Spatial variations in mortality were not simply the result of occupational status differences as mortality from white collar groups was also elevated in inland areas. Spatial variation in mortality was not diluted due to the impact of immigration.

CONCLUSIONS

Particular subgroups of people remained at risk and it is likely that differential access to ambulance services and travel time contribute, more particularly in inland rural areas.

IMPLICATIONS

Groups at risk need to be more precisely targeted for preventative measures and public health initiatives, with particular implications for groups in inland rural areas, the Hunter Region, and outer lower income areas of Sydney.

Quantitative health research in an emerging information economy

This paper is concerned with the changing information environment in the U.K. National Health Service and its implications for the quantitative analysis of health and health care. The traditionally available data series are contrasted with those sources that are being created or enhanced as a result of the post-1991 market-orientation of the health care system. The likely research implications of the commodification of health data are assessed and illustrated with reference to the specific example of the geography of asthma. The paper warns against a future in which large-scale quantitative health research is only possible in relation to projects which may yield direct financial or market benefits to the data providers.

The public health risks of Lyme disease in Breckland, U.K.: an investigation of environmental and social factors

This paper considers the public health risks of Lyme disease, a borrelial infection transmitted to humans chiefly by nymphal Ixodes ticks. A study undertaken in the Breckland area of East Anglia, U.K., combined analysis of the spatial and temporal factors affecting tick activity at recreational sites with a survey of current levels of disease awareness among visitors to these locations. Significant relationships were found between densities of questing ticks and vegetation type, relative humidity and temperature. More than two thirds of the general public visiting the sites were aware ticks could carry diseases, but only 13% recognized an unfed nymph, and under half knew that Lyme disease could be contracted from tick bites. Such results need to be taken into account when formulating public health and education measures.

Applied epidemiology and environmental health: emerging controversies

This review article assesses the state of the science in environmental epidemiology, not by summarizing current scientific findings but rather by examining conceptual controversies in the study of how environmental factors influence human health. This approach seems necessary because environmental epidemiology presently stands at a crossroads-in fact, at a number of overlapping crossroads. The field teems with epistemologic debates concerning appropriate paradigms for framing research questions, interpreting data, and applying research findings to policy. The present review focuses on emerging controversies related to three questions: What is considered "environmental"? What counts as credible research in environmental epidemiology? And what does "applied epidemiology" mean in the context of environmental health? The goal is to organize the presently fragmented critical literature on these issues and to promote productive dialogue by identifying central themes in current conceptual debates.

Geographic information systems, spatial network analysis, and contraceptive choice

How does family planning accessibility affect contraceptive choice? In this paper we use techniques of spatial analysis to develop measures of family planning accessibility, and evaluate the effects of these geographically derived measures in a multilevel statistical model of temporary method choice in Nang Rong, Thailand. In our analyses we combine spatial data obtained from maps and Global Positioning System (GPS) readings with sociodemographic data from surveys and administrative records. The new measures reveal (1) important travel time effects even when family planning outlets are close by; (2) independent effects of road composition; (3) the relevance of alternative sources of family planning supply; and (4) the importance of the local history of program placement.

Psychosocial stress, women and heart health: a critical review

This paper reports the results of a systematic critical appraisal of the research literature designed to determine the balance of evidence for the role of psychosocial stress as a risk factor in women's coronary disease. The study is placed within a larger research programme which addresses geographic variation in heart disease among women. The scope of the research is based on the burden of illness that coronary disease represents, existing geographic variation in morbidity and mortality, the role of psychosocial stress as a potential risk factor for women given changing gender roles, and the relative lack of attention paid to both the etiology and epidemiology of women's coronary disease in the research literature. In fact, there is very little original research, the balance of which provides equivocal evidence of a link between psychosocial stress and coronary disease in women but enough to suggest a need for further etiologic research. This need is substantiated by the appearance of a perception among the general population that 'stress' 'causes' heart disease. In addition, it would seem that 'stress' and 'heart disease' are major health concerns for women. Given the dichotomy between actual and perceived etiologic links, there perhaps needs to be an adjustment made with respect to research focus which addresses the role of perceived environmental stress as well as the individual in defining health and well-being. That is, the relationship between psychosocial stress and heart disease may depend upon the meaning of the situation to the individual and the way she perceives her life situation. Medical geographers are well-placed to address these research issues using a combination of qualitative and quantitative approaches.