[Geographic differences of bronchopulmonary cancer mortality in France and spatial scales of analysis: significance of scale change in health geography].

Background: It is important to choose a valid spatial scale to study health differences in a geographical perspective. Many scales can be valid and a combination is required to understand the spatial distribution of a given health problem. Geographic distribution of lung cancer was studied in France using different scales to illustrate the importance of changing scales in health geography.
Methods: Standardized rates (direct method) for lung cancer were calculated for the period 1988-92 and mapped at different scales.
Results: Original spatial structure was observed for each scale. This proved that different interactions occur at each scale between environmental and social factors. Changing the scale allowed a better understanding of variations in the spatial distribution of lung cancer.
Conclusions: The validity of a regional scale to study health geographical distributions is questioned. Changing the scale would allow proposing action to improve health promotion.