Why is NARCRMS data collection limited to 5 years per patient?

Why is NARCRMS data collection limited to 5 years per patient?

The first five years is the pilot phase of NARCRMS.  After five years, NARCRMS will consider expanding the registry to include sites all over the world, or develop a plan for federating the database to allow searches to be performed on valuable MS data sets that reside in different locations outside of the US. Such expansion would make it an even more valuable resource for the scientific, medical and regulatory community.

6/15/2016