For clinical research you have to learn Clinical SAS.

There is a difference between SAS and Clinical SAS.

Base SAS provides a scalable,integrated software environment specially designed for the data access,transformation and reporting.It includes a 4th generation programming language; ready to use programs for data manipulation,information storage and retrieval,descriptive statistics and report writing;and a powerful macro facility that reduces programming time and maintenance headaches.

Clinical SAS and all its features including major concepts behind SAS clinical Data integration organizes,standardizes and manages clinical research data and metadata,Import and Export,Macro Programming for a large data and become certified. 

Though it's not a compulsion but its a boon for sure. It is always prefered and has a much more technical knowledge than any other which makes it very scope full.