By using the 11-digit Norwegian personal number it is possible to merge HUNT data with other Norwegian  registries (if described in the protocol and approved by the Regional Ethical Committee (REK)). 

The Principle Investigator (PI) has the responsibility for obtaining approval from the registries intended merged, and for payment for data delivery from the registries. 

If the registry of interest is not a health register, other rules apply, which vary depending on the type of data (anonymous, de-identified, identifiable). The registries themselves will be able to inform you of their procedures. 

Please note that not all registries in Norway are allowed to deliver data to researchers abroad.

Merging in practice

The usual procedure for merging one or more health registries with HUNT data is:

1. The PI applies for the use of data at the various registries of interest.
2. When approval is obtained, PI sends HUNT the reference number and contact details for the person/institute handling the case at the registry.
3. HUNT databank delivers a datafile with HUNT data to the PI. Each case in the file will have a unique, project -specific ID (PID). HUNT databank sends the bridge with personal number - project ID to the registry of interest.
4. The registry creates a file with persons who participated in HUNT and sends a file from the registry to the PI - cases will have the same project specific number.
5. PI merges the files on PID.

For information on some national registries, and more explanations of merging data, please see helsedata.no on kobling av flere datakilder.