1.1 Purposes of health analysis

This learning object considers the scope and purpose of the analysis of health. It introduces the existence of many distinct patterns in health. Realisation that these patterns exist leads us to seek causal explanations and to develop policies aimed at the reduction of disease and the improvement of quality of life.

Even the most cursory examination reveals marked variations in the health of populations. While epidemic spread is observable in specific regions over short periods of time, some patterns of ill health endure over decades and even centuries. For the most part, these variations are not random, but are observable at global, national and local scales and across socio-economic groups, races and genders.

 
In addition to these well-established patterns, there is evidence for instances such as the increased incidence of childhood thyroid cancer following the Chernobyl nuclear disaster in 1986, in which a specific human impact on the environment had health effects which were not previously recognised (Baverstock, 1998). The monitoring of health and disease data does not usually lead directly to new medical discoveries, but the analysis of health in order to seek out the causal processes underlying specific diseases has a long tradition. Knowledge gained from the analysis of health data more often informs specific preventive interventions such as vaccination programmes to control epidemic spread and the allocation of health care resources in such a way that most effort is directed towards those places and population groups with the greatest needs.

Interventions resulting from health analysis may be medical or social, including education and health service planning. Adopting a narrow biomedical view of health as the absence of disease tends to result in consideration of interventions that only have narrow biomedical impacts. By contrast, consideration of health in the broader context of the physical and social environment necessarily leads to recommendations about broader aspects of health care and social policy. Implications for social policy are contentious because they frequently challenge established value systems and implicate the redistribution of resources – between the nations of the world or between advantaged and disadvantaged groups within a society.

Whoever wishes to investigate medicine properly, should proceed thus: in the first place to consider the seasons of the year, and what effects each of them produces for they are not at all alike, but differ much from themselves in regard to their changes. Then the winds, the hot and the cold, especially such as are common to all countries, and then such as are peculiar to each locality. We must also consider the qualities of the waters, for as they differ from one another in taste and weight, so also do they differ much in their qualities . . . and the mode in which the inhabitants live, and what are their pursuits, whether they are fond of drinking and eating to excess, and given to indolence, or are fond of exercise and labor, and not given to excess in eating and drinking.

(Hippocrates, On Airs, Waters and Places)

 

This quotation from Hippocrates, dating from around 400 BC, has often been cited by those with an interest in the geography of health as it demonstrates a view of health that is much broader than the identification of specific physical ailments, recognising the importance of the whole environment on the health experience of the population. This reasoning is central to the analysis of health data and particularly to the geographical perspective, within which there is a strong cartographic tradition, mapping patterns of disease in order to understand relationships between disease incidence and other factors. In later centuries the balance of importance attached to purely biomedical and broader social and environmental explanations has been strongly contested.

Appropriate GIS use in the analysis of health requires that the GIS practitioner have a broad understanding of the purposes and expectations of analysis. A geographical perspective can bring unique insights to patterns of health alongside those from the biomedical, environmental and social sciences. As one example, Christopherson, Dix and Rooney (1999) look at geographic patterns in road traffic accidents and use GIS to compare two different data sets – one collected by a health department in government and the other by a transport department. There are of course many other reasons for undertaking such analyses.

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