Principles of immigration epidemiology

Immigration epidemiology can estimate the relationship between genetic factors and environmental factors of diseases by comparing the incidence or mortality rates of the same people living in different areas or comparing the incidence or mortality rates of different people living in the same area. proportion. If the incidence rates of two parts of the same population differ greatly after living in different areas for a period of time, it can be estimated that environmental factors account for a larger proportion of the disease; conversely, if the incidence rates of different populations in the same area vary greatly, it can be estimated It is estimated that genetic factors may play a greater role. It can be expressed in the following simple form.

CO is the mortality rate of a certain disease in the country of origin, M is the mortality rate of immigrants, and CA is the mortality rate in the country of immigration.

1. If environmental factors are the cause of the observed changes in mortality, then it can be seen that CO is different from M, and the M value will gradually approach CA over time.

2. If genetic factors are responsible for the observed changes in mortality, it can be seen that CO and M are the same, and CO, M and CA are different.