How can the data to be merged?

Given the numerous data sources listed in Chapter 5 of the textbook,(Epidemiology for Public Health Practice 5thEdition) select two data sources that could be linked to create an enriched data set for a specific public health research purpose. What are public health concerns that the linked data could be used to investigate? Explain your choices. 

TWO DATA SOURCES CHOSEN: CLINICAL DATA SOURCES & INSURANCE DATA.

Please take into account the following:

1. How can the data to be merged?

2. Nature of the data, how it was collected.

3. Unique variables that each dataset is bringing to the discussion.