7. Conclusion

Spatial analysis for epidemiology is a rich and varied field, with, as we have seen in this article, numerous methods and techniques. Spatial and spatio-temporal analysis is necessary to understand how health phenomena work, whether from an epidemiological point of view or for geographic analysis. But it's also a difficult field, because as we've pointed out throughout this article, there are many restrictions to take into account:

• data quality must always be questioned;

• you have to be careful about aggregation and scale transfers;

• analyses are often too simple and do not reflect the complexity of reality (distance and connectivity calculations, natural barriers);

• spatial interactions can be density-dependent;

• ...