Bridge coding in cause-of-death statistics is an exercise in which the same group of deaths are independently classified according to two different classifications or coding methods.
Usually, the group of deaths consists of the total or a sample of one year’s deaths. The different classifications can be:
- ICD-9 versus ICD-10
- manual coding versus automated coding;
- different ICD-10 updates.
Comparing the differences in the underlying cause-of-death statistics resulting from two methods, makes it possible to better understand the impact of changing classification on cause-specific mortality trends.